author | haftmann |
Sun, 21 Sep 2014 16:56:11 +0200 | |
changeset 58410 | 6d46ad54a2ab |
parent 58310 | 91ea607a34d8 |
child 58710 | 7216a10d69ba |
permissions | -rw-r--r-- |
33154 | 1 |
(* Title: HOL/Decision_Procs/Reflected_Multivariate_Polynomial.thy |
2 |
Author: Amine Chaieb |
|
3 |
*) |
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4 |
||
35046 | 5 |
header {* Implementation and verification of multivariate polynomials *} |
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theory Reflected_Multivariate_Polynomial |
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imports Complex_Main Rat_Pair Polynomial_List |
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begin |
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||
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subsection{* Datatype of polynomial expressions *} |
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|
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datatype poly = C Num | Bound nat | Add poly poly | Sub poly poly |
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| Mul poly poly| Neg poly| Pw poly nat| CN poly nat poly |
15 |
||
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abbreviation poly_0 :: "poly" ("0\<^sub>p") where "0\<^sub>p \<equiv> C (0\<^sub>N)" |
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abbreviation poly_p :: "int \<Rightarrow> poly" ("'((_)')\<^sub>p") where "(i)\<^sub>p \<equiv> C (i)\<^sub>N" |
33154 | 18 |
|
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|
33154 | 20 |
subsection{* Boundedness, substitution and all that *} |
52658 | 21 |
|
22 |
primrec polysize:: "poly \<Rightarrow> nat" |
|
23 |
where |
|
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"polysize (C c) = 1" |
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| "polysize (Bound n) = 1" |
26 |
| "polysize (Neg p) = 1 + polysize p" |
|
27 |
| "polysize (Add p q) = 1 + polysize p + polysize q" |
|
28 |
| "polysize (Sub p q) = 1 + polysize p + polysize q" |
|
29 |
| "polysize (Mul p q) = 1 + polysize p + polysize q" |
|
30 |
| "polysize (Pw p n) = 1 + polysize p" |
|
31 |
| "polysize (CN c n p) = 4 + polysize c + polysize p" |
|
33154 | 32 |
|
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primrec polybound0:: "poly \<Rightarrow> bool" -- {* a poly is INDEPENDENT of Bound 0 *} |
34 |
where |
|
56000 | 35 |
"polybound0 (C c) \<longleftrightarrow> True" |
36 |
| "polybound0 (Bound n) \<longleftrightarrow> n > 0" |
|
37 |
| "polybound0 (Neg a) \<longleftrightarrow> polybound0 a" |
|
38 |
| "polybound0 (Add a b) \<longleftrightarrow> polybound0 a \<and> polybound0 b" |
|
39 |
| "polybound0 (Sub a b) \<longleftrightarrow> polybound0 a \<and> polybound0 b" |
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40 |
| "polybound0 (Mul a b) \<longleftrightarrow> polybound0 a \<and> polybound0 b" |
|
41 |
| "polybound0 (Pw p n) \<longleftrightarrow> polybound0 p" |
|
42 |
| "polybound0 (CN c n p) \<longleftrightarrow> n \<noteq> 0 \<and> polybound0 c \<and> polybound0 p" |
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39246 | 43 |
|
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primrec polysubst0:: "poly \<Rightarrow> poly \<Rightarrow> poly" -- {* substitute a poly into a poly for Bound 0 *} |
45 |
where |
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56000 | 46 |
"polysubst0 t (C c) = C c" |
47 |
| "polysubst0 t (Bound n) = (if n = 0 then t else Bound n)" |
|
39246 | 48 |
| "polysubst0 t (Neg a) = Neg (polysubst0 t a)" |
49 |
| "polysubst0 t (Add a b) = Add (polysubst0 t a) (polysubst0 t b)" |
|
52803 | 50 |
| "polysubst0 t (Sub a b) = Sub (polysubst0 t a) (polysubst0 t b)" |
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| "polysubst0 t (Mul a b) = Mul (polysubst0 t a) (polysubst0 t b)" |
52 |
| "polysubst0 t (Pw p n) = Pw (polysubst0 t p) n" |
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56000 | 53 |
| "polysubst0 t (CN c n p) = |
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(if n = 0 then Add (polysubst0 t c) (Mul t (polysubst0 t p)) |
|
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else CN (polysubst0 t c) n (polysubst0 t p))" |
|
33154 | 56 |
|
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fun decrpoly:: "poly \<Rightarrow> poly" |
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where |
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"decrpoly (Bound n) = Bound (n - 1)" |
41808 | 60 |
| "decrpoly (Neg a) = Neg (decrpoly a)" |
61 |
| "decrpoly (Add a b) = Add (decrpoly a) (decrpoly b)" |
|
62 |
| "decrpoly (Sub a b) = Sub (decrpoly a) (decrpoly b)" |
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63 |
| "decrpoly (Mul a b) = Mul (decrpoly a) (decrpoly b)" |
|
64 |
| "decrpoly (Pw p n) = Pw (decrpoly p) n" |
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65 |
| "decrpoly (CN c n p) = CN (decrpoly c) (n - 1) (decrpoly p)" |
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66 |
| "decrpoly a = a" |
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33154 | 67 |
|
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|
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subsection{* Degrees and heads and coefficients *} |
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||
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fun degree :: "poly \<Rightarrow> nat" |
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where |
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"degree (CN c 0 p) = 1 + degree p" |
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| "degree p = 0" |
33154 | 75 |
|
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fun head :: "poly \<Rightarrow> poly" |
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where |
33154 | 78 |
"head (CN c 0 p) = head p" |
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| "head p = p" |
80 |
||
81 |
(* More general notions of degree and head *) |
|
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fun degreen :: "poly \<Rightarrow> nat \<Rightarrow> nat" |
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where |
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"degreen (CN c n p) = (\<lambda>m. if n = m then 1 + degreen p n else 0)" |
85 |
| "degreen p = (\<lambda>m. 0)" |
|
33154 | 86 |
|
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fun headn :: "poly \<Rightarrow> nat \<Rightarrow> poly" |
41808 | 88 |
where |
89 |
"headn (CN c n p) = (\<lambda>m. if n \<le> m then headn p m else CN c n p)" |
|
90 |
| "headn p = (\<lambda>m. p)" |
|
33154 | 91 |
|
56207 | 92 |
fun coefficients :: "poly \<Rightarrow> poly list" |
41808 | 93 |
where |
56000 | 94 |
"coefficients (CN c 0 p) = c # coefficients p" |
41808 | 95 |
| "coefficients p = [p]" |
33154 | 96 |
|
56207 | 97 |
fun isconstant :: "poly \<Rightarrow> bool" |
41808 | 98 |
where |
99 |
"isconstant (CN c 0 p) = False" |
|
100 |
| "isconstant p = True" |
|
33154 | 101 |
|
56207 | 102 |
fun behead :: "poly \<Rightarrow> poly" |
41808 | 103 |
where |
104 |
"behead (CN c 0 p) = (let p' = behead p in if p' = 0\<^sub>p then c else CN c 0 p')" |
|
105 |
| "behead p = 0\<^sub>p" |
|
106 |
||
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fun headconst :: "poly \<Rightarrow> Num" |
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where |
33154 | 109 |
"headconst (CN c n p) = headconst p" |
41808 | 110 |
| "headconst (C n) = n" |
33154 | 111 |
|
52658 | 112 |
|
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subsection{* Operations for normalization *} |
41812 | 114 |
|
115 |
declare if_cong[fundef_cong del] |
|
116 |
declare let_cong[fundef_cong del] |
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117 |
||
118 |
fun polyadd :: "poly \<Rightarrow> poly \<Rightarrow> poly" (infixl "+\<^sub>p" 60) |
|
119 |
where |
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56000 | 120 |
"polyadd (C c) (C c') = C (c +\<^sub>N c')" |
52803 | 121 |
| "polyadd (C c) (CN c' n' p') = CN (polyadd (C c) c') n' p'" |
41812 | 122 |
| "polyadd (CN c n p) (C c') = CN (polyadd c (C c')) n p" |
123 |
| "polyadd (CN c n p) (CN c' n' p') = |
|
124 |
(if n < n' then CN (polyadd c (CN c' n' p')) n p |
|
56000 | 125 |
else if n' < n then CN (polyadd (CN c n p) c') n' p' |
126 |
else |
|
127 |
let |
|
128 |
cc' = polyadd c c'; |
|
129 |
pp' = polyadd p p' |
|
130 |
in if pp' = 0\<^sub>p then cc' else CN cc' n pp')" |
|
41812 | 131 |
| "polyadd a b = Add a b" |
132 |
||
33154 | 133 |
|
41808 | 134 |
fun polyneg :: "poly \<Rightarrow> poly" ("~\<^sub>p") |
135 |
where |
|
33154 | 136 |
"polyneg (C c) = C (~\<^sub>N c)" |
41808 | 137 |
| "polyneg (CN c n p) = CN (polyneg c) n (polyneg p)" |
138 |
| "polyneg a = Neg a" |
|
33154 | 139 |
|
41814 | 140 |
definition polysub :: "poly \<Rightarrow> poly \<Rightarrow> poly" (infixl "-\<^sub>p" 60) |
52658 | 141 |
where "p -\<^sub>p q = polyadd p (polyneg q)" |
41813 | 142 |
|
143 |
fun polymul :: "poly \<Rightarrow> poly \<Rightarrow> poly" (infixl "*\<^sub>p" 60) |
|
144 |
where |
|
56043 | 145 |
"polymul (C c) (C c') = C (c *\<^sub>N c')" |
52803 | 146 |
| "polymul (C c) (CN c' n' p') = |
56000 | 147 |
(if c = 0\<^sub>N then 0\<^sub>p else CN (polymul (C c) c') n' (polymul (C c) p'))" |
52803 | 148 |
| "polymul (CN c n p) (C c') = |
56000 | 149 |
(if c' = 0\<^sub>N then 0\<^sub>p else CN (polymul c (C c')) n (polymul p (C c')))" |
52803 | 150 |
| "polymul (CN c n p) (CN c' n' p') = |
56000 | 151 |
(if n < n' then CN (polymul c (CN c' n' p')) n (polymul p (CN c' n' p')) |
152 |
else if n' < n then CN (polymul (CN c n p) c') n' (polymul (CN c n p) p') |
|
153 |
else polyadd (polymul (CN c n p) c') (CN 0\<^sub>p n' (polymul (CN c n p) p')))" |
|
41813 | 154 |
| "polymul a b = Mul a b" |
41808 | 155 |
|
41812 | 156 |
declare if_cong[fundef_cong] |
157 |
declare let_cong[fundef_cong] |
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158 |
||
41808 | 159 |
fun polypow :: "nat \<Rightarrow> poly \<Rightarrow> poly" |
160 |
where |
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161 |
"polypow 0 = (\<lambda>p. (1)\<^sub>p)" |
56000 | 162 |
| "polypow n = |
163 |
(\<lambda>p. |
|
164 |
let |
|
165 |
q = polypow (n div 2) p; |
|
166 |
d = polymul q q |
|
167 |
in if even n then d else polymul p d)" |
|
33154 | 168 |
|
35054 | 169 |
abbreviation poly_pow :: "poly \<Rightarrow> nat \<Rightarrow> poly" (infixl "^\<^sub>p" 60) |
170 |
where "a ^\<^sub>p k \<equiv> polypow k a" |
|
33154 | 171 |
|
41808 | 172 |
function polynate :: "poly \<Rightarrow> poly" |
173 |
where |
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174 |
"polynate (Bound n) = CN 0\<^sub>p n (1)\<^sub>p" |
56000 | 175 |
| "polynate (Add p q) = polynate p +\<^sub>p polynate q" |
176 |
| "polynate (Sub p q) = polynate p -\<^sub>p polynate q" |
|
177 |
| "polynate (Mul p q) = polynate p *\<^sub>p polynate q" |
|
178 |
| "polynate (Neg p) = ~\<^sub>p (polynate p)" |
|
179 |
| "polynate (Pw p n) = polynate p ^\<^sub>p n" |
|
41808 | 180 |
| "polynate (CN c n p) = polynate (Add c (Mul (Bound n) p))" |
181 |
| "polynate (C c) = C (normNum c)" |
|
182 |
by pat_completeness auto |
|
183 |
termination by (relation "measure polysize") auto |
|
33154 | 184 |
|
52658 | 185 |
fun poly_cmul :: "Num \<Rightarrow> poly \<Rightarrow> poly" |
186 |
where |
|
33154 | 187 |
"poly_cmul y (C x) = C (y *\<^sub>N x)" |
188 |
| "poly_cmul y (CN c n p) = CN (poly_cmul y c) n (poly_cmul y p)" |
|
189 |
| "poly_cmul y p = C y *\<^sub>p p" |
|
190 |
||
56009 | 191 |
definition monic :: "poly \<Rightarrow> poly \<times> bool" |
56000 | 192 |
where |
193 |
"monic p = |
|
194 |
(let h = headconst p |
|
195 |
in if h = 0\<^sub>N then (p, False) else (C (Ninv h) *\<^sub>p p, 0>\<^sub>N h))" |
|
33154 | 196 |
|
52658 | 197 |
|
56000 | 198 |
subsection {* Pseudo-division *} |
33154 | 199 |
|
52658 | 200 |
definition shift1 :: "poly \<Rightarrow> poly" |
56000 | 201 |
where "shift1 p = CN 0\<^sub>p 0 p" |
33154 | 202 |
|
56009 | 203 |
abbreviation funpow :: "nat \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" |
52658 | 204 |
where "funpow \<equiv> compow" |
39246 | 205 |
|
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206 |
partial_function (tailrec) polydivide_aux :: "poly \<Rightarrow> nat \<Rightarrow> poly \<Rightarrow> nat \<Rightarrow> poly \<Rightarrow> nat \<times> poly" |
52658 | 207 |
where |
52803 | 208 |
"polydivide_aux a n p k s = |
56000 | 209 |
(if s = 0\<^sub>p then (k, s) |
52803 | 210 |
else |
56000 | 211 |
let |
212 |
b = head s; |
|
213 |
m = degree s |
|
214 |
in |
|
215 |
if m < n then (k,s) |
|
216 |
else |
|
217 |
let p' = funpow (m - n) shift1 p |
|
218 |
in |
|
219 |
if a = b then polydivide_aux a n p k (s -\<^sub>p p') |
|
220 |
else polydivide_aux a n p (Suc k) ((a *\<^sub>p s) -\<^sub>p (b *\<^sub>p p')))" |
|
33154 | 221 |
|
56000 | 222 |
definition polydivide :: "poly \<Rightarrow> poly \<Rightarrow> nat \<times> poly" |
223 |
where "polydivide s p = polydivide_aux (head p) (degree p) p 0 s" |
|
33154 | 224 |
|
52658 | 225 |
fun poly_deriv_aux :: "nat \<Rightarrow> poly \<Rightarrow> poly" |
226 |
where |
|
33154 | 227 |
"poly_deriv_aux n (CN c 0 p) = CN (poly_cmul ((int n)\<^sub>N) c) 0 (poly_deriv_aux (n + 1) p)" |
228 |
| "poly_deriv_aux n p = poly_cmul ((int n)\<^sub>N) p" |
|
229 |
||
52658 | 230 |
fun poly_deriv :: "poly \<Rightarrow> poly" |
231 |
where |
|
33154 | 232 |
"poly_deriv (CN c 0 p) = poly_deriv_aux 1 p" |
233 |
| "poly_deriv p = 0\<^sub>p" |
|
234 |
||
52658 | 235 |
|
33154 | 236 |
subsection{* Semantics of the polynomial representation *} |
237 |
||
56000 | 238 |
primrec Ipoly :: "'a list \<Rightarrow> poly \<Rightarrow> 'a::{field_char_0,field_inverse_zero,power}" |
239 |
where |
|
33154 | 240 |
"Ipoly bs (C c) = INum c" |
39246 | 241 |
| "Ipoly bs (Bound n) = bs!n" |
242 |
| "Ipoly bs (Neg a) = - Ipoly bs a" |
|
243 |
| "Ipoly bs (Add a b) = Ipoly bs a + Ipoly bs b" |
|
244 |
| "Ipoly bs (Sub a b) = Ipoly bs a - Ipoly bs b" |
|
245 |
| "Ipoly bs (Mul a b) = Ipoly bs a * Ipoly bs b" |
|
56000 | 246 |
| "Ipoly bs (Pw t n) = Ipoly bs t ^ n" |
247 |
| "Ipoly bs (CN c n p) = Ipoly bs c + (bs!n) * Ipoly bs p" |
|
39246 | 248 |
|
56000 | 249 |
abbreviation Ipoly_syntax :: "poly \<Rightarrow> 'a list \<Rightarrow>'a::{field_char_0,field_inverse_zero,power}" |
250 |
("\<lparr>_\<rparr>\<^sub>p\<^bsup>_\<^esup>") |
|
35054 | 251 |
where "\<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<equiv> Ipoly bs p" |
33154 | 252 |
|
56009 | 253 |
lemma Ipoly_CInt: "Ipoly bs (C (i, 1)) = of_int i" |
33154 | 254 |
by (simp add: INum_def) |
56000 | 255 |
|
52803 | 256 |
lemma Ipoly_CRat: "Ipoly bs (C (i, j)) = of_int i / of_int j" |
33154 | 257 |
by (simp add: INum_def) |
258 |
||
259 |
lemmas RIpoly_eqs = Ipoly.simps(2-7) Ipoly_CInt Ipoly_CRat |
|
260 |
||
52658 | 261 |
|
33154 | 262 |
subsection {* Normal form and normalization *} |
263 |
||
41808 | 264 |
fun isnpolyh:: "poly \<Rightarrow> nat \<Rightarrow> bool" |
265 |
where |
|
33154 | 266 |
"isnpolyh (C c) = (\<lambda>k. isnormNum c)" |
56000 | 267 |
| "isnpolyh (CN c n p) = (\<lambda>k. n \<ge> k \<and> isnpolyh c (Suc n) \<and> isnpolyh p n \<and> p \<noteq> 0\<^sub>p)" |
41808 | 268 |
| "isnpolyh p = (\<lambda>k. False)" |
33154 | 269 |
|
56000 | 270 |
lemma isnpolyh_mono: "n' \<le> n \<Longrightarrow> isnpolyh p n \<Longrightarrow> isnpolyh p n'" |
52658 | 271 |
by (induct p rule: isnpolyh.induct) auto |
33154 | 272 |
|
52658 | 273 |
definition isnpoly :: "poly \<Rightarrow> bool" |
56000 | 274 |
where "isnpoly p = isnpolyh p 0" |
33154 | 275 |
|
276 |
text{* polyadd preserves normal forms *} |
|
277 |
||
56000 | 278 |
lemma polyadd_normh: "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> isnpolyh (polyadd p q) (min n0 n1)" |
52803 | 279 |
proof (induct p q arbitrary: n0 n1 rule: polyadd.induct) |
41812 | 280 |
case (2 ab c' n' p' n0 n1) |
56009 | 281 |
from 2 have th1: "isnpolyh (C ab) (Suc n')" |
282 |
by simp |
|
283 |
from 2(3) have th2: "isnpolyh c' (Suc n')" and nplen1: "n' \<ge> n1" |
|
284 |
by simp_all |
|
285 |
with isnpolyh_mono have cp: "isnpolyh c' (Suc n')" |
|
286 |
by simp |
|
287 |
with 2(1)[OF th1 th2] have th3:"isnpolyh (C ab +\<^sub>p c') (Suc n')" |
|
288 |
by simp |
|
289 |
from nplen1 have n01len1: "min n0 n1 \<le> n'" |
|
290 |
by simp |
|
291 |
then show ?case using 2 th3 |
|
292 |
by simp |
|
33154 | 293 |
next |
41812 | 294 |
case (3 c' n' p' ab n1 n0) |
56009 | 295 |
from 3 have th1: "isnpolyh (C ab) (Suc n')" |
296 |
by simp |
|
297 |
from 3(2) have th2: "isnpolyh c' (Suc n')" and nplen1: "n' \<ge> n1" |
|
298 |
by simp_all |
|
299 |
with isnpolyh_mono have cp: "isnpolyh c' (Suc n')" |
|
300 |
by simp |
|
301 |
with 3(1)[OF th2 th1] have th3:"isnpolyh (c' +\<^sub>p C ab) (Suc n')" |
|
302 |
by simp |
|
303 |
from nplen1 have n01len1: "min n0 n1 \<le> n'" |
|
304 |
by simp |
|
305 |
then show ?case using 3 th3 |
|
306 |
by simp |
|
33154 | 307 |
next |
308 |
case (4 c n p c' n' p' n0 n1) |
|
56009 | 309 |
then have nc: "isnpolyh c (Suc n)" and np: "isnpolyh p n" |
310 |
by simp_all |
|
311 |
from 4 have nc': "isnpolyh c' (Suc n')" and np': "isnpolyh p' n'" |
|
312 |
by simp_all |
|
313 |
from 4 have ngen0: "n \<ge> n0" |
|
314 |
by simp |
|
315 |
from 4 have n'gen1: "n' \<ge> n1" |
|
316 |
by simp |
|
317 |
have "n < n' \<or> n' < n \<or> n = n'" |
|
318 |
by auto |
|
319 |
moreover |
|
320 |
{ |
|
52803 | 321 |
assume eq: "n = n'" |
322 |
with "4.hyps"(3)[OF nc nc'] |
|
56009 | 323 |
have ncc':"isnpolyh (c +\<^sub>p c') (Suc n)" |
324 |
by auto |
|
325 |
then have ncc'n01: "isnpolyh (c +\<^sub>p c') (min n0 n1)" |
|
326 |
using isnpolyh_mono[where n'="min n0 n1" and n="Suc n"] ngen0 n'gen1 |
|
327 |
by auto |
|
328 |
from eq "4.hyps"(4)[OF np np'] have npp': "isnpolyh (p +\<^sub>p p') n" |
|
329 |
by simp |
|
330 |
have minle: "min n0 n1 \<le> n'" |
|
331 |
using ngen0 n'gen1 eq by simp |
|
332 |
from minle npp' ncc'n01 4 eq ngen0 n'gen1 ncc' have ?case |
|
333 |
by (simp add: Let_def) |
|
334 |
} |
|
335 |
moreover |
|
336 |
{ |
|
52803 | 337 |
assume lt: "n < n'" |
56009 | 338 |
have "min n0 n1 \<le> n0" |
339 |
by simp |
|
340 |
with 4 lt have th1:"min n0 n1 \<le> n" |
|
341 |
by auto |
|
342 |
from 4 have th21: "isnpolyh c (Suc n)" |
|
343 |
by simp |
|
344 |
from 4 have th22: "isnpolyh (CN c' n' p') n'" |
|
345 |
by simp |
|
346 |
from lt have th23: "min (Suc n) n' = Suc n" |
|
347 |
by arith |
|
348 |
from "4.hyps"(1)[OF th21 th22] have "isnpolyh (polyadd c (CN c' n' p')) (Suc n)" |
|
349 |
using th23 by simp |
|
350 |
with 4 lt th1 have ?case |
|
351 |
by simp |
|
352 |
} |
|
353 |
moreover |
|
354 |
{ |
|
355 |
assume gt: "n' < n" |
|
356 |
then have gt': "n' < n \<and> \<not> n < n'" |
|
357 |
by simp |
|
358 |
have "min n0 n1 \<le> n1" |
|
359 |
by simp |
|
360 |
with 4 gt have th1: "min n0 n1 \<le> n'" |
|
361 |
by auto |
|
362 |
from 4 have th21: "isnpolyh c' (Suc n')" |
|
363 |
by simp_all |
|
364 |
from 4 have th22: "isnpolyh (CN c n p) n" |
|
365 |
by simp |
|
366 |
from gt have th23: "min n (Suc n') = Suc n'" |
|
367 |
by arith |
|
368 |
from "4.hyps"(2)[OF th22 th21] have "isnpolyh (polyadd (CN c n p) c') (Suc n')" |
|
369 |
using th23 by simp |
|
370 |
with 4 gt th1 have ?case |
|
371 |
by simp |
|
372 |
} |
|
52803 | 373 |
ultimately show ?case by blast |
33154 | 374 |
qed auto |
375 |
||
41812 | 376 |
lemma polyadd[simp]: "Ipoly bs (polyadd p q) = Ipoly bs p + Ipoly bs q" |
52658 | 377 |
by (induct p q rule: polyadd.induct) |
378 |
(auto simp add: Let_def field_simps distrib_left[symmetric] simp del: distrib_left) |
|
33154 | 379 |
|
56009 | 380 |
lemma polyadd_norm: "isnpoly p \<Longrightarrow> isnpoly q \<Longrightarrow> isnpoly (polyadd p q)" |
33154 | 381 |
using polyadd_normh[of "p" "0" "q" "0"] isnpoly_def by simp |
382 |
||
41404 | 383 |
text{* The degree of addition and other general lemmas needed for the normal form of polymul *} |
33154 | 384 |
|
52803 | 385 |
lemma polyadd_different_degreen: |
56009 | 386 |
assumes "isnpolyh p n0" |
387 |
and "isnpolyh q n1" |
|
388 |
and "degreen p m \<noteq> degreen q m" |
|
389 |
and "m \<le> min n0 n1" |
|
390 |
shows "degreen (polyadd p q) m = max (degreen p m) (degreen q m)" |
|
391 |
using assms |
|
33154 | 392 |
proof (induct p q arbitrary: m n0 n1 rule: polyadd.induct) |
393 |
case (4 c n p c' n' p' m n0 n1) |
|
41763 | 394 |
have "n' = n \<or> n < n' \<or> n' < n" by arith |
56009 | 395 |
then show ?case |
41763 | 396 |
proof (elim disjE) |
397 |
assume [simp]: "n' = n" |
|
41812 | 398 |
from 4(4)[of n n m] 4(3)[of "Suc n" "Suc n" m] 4(5-7) |
41763 | 399 |
show ?thesis by (auto simp: Let_def) |
400 |
next |
|
401 |
assume "n < n'" |
|
402 |
with 4 show ?thesis by auto |
|
403 |
next |
|
404 |
assume "n' < n" |
|
405 |
with 4 show ?thesis by auto |
|
406 |
qed |
|
407 |
qed auto |
|
33154 | 408 |
|
56009 | 409 |
lemma headnz[simp]: "isnpolyh p n \<Longrightarrow> p \<noteq> 0\<^sub>p \<Longrightarrow> headn p m \<noteq> 0\<^sub>p" |
52658 | 410 |
by (induct p arbitrary: n rule: headn.induct) auto |
56009 | 411 |
|
33154 | 412 |
lemma degree_isnpolyh_Suc[simp]: "isnpolyh p (Suc n) \<Longrightarrow> degree p = 0" |
52658 | 413 |
by (induct p arbitrary: n rule: degree.induct) auto |
56009 | 414 |
|
33154 | 415 |
lemma degreen_0[simp]: "isnpolyh p n \<Longrightarrow> m < n \<Longrightarrow> degreen p m = 0" |
52658 | 416 |
by (induct p arbitrary: n rule: degreen.induct) auto |
33154 | 417 |
|
418 |
lemma degree_isnpolyh_Suc': "n > 0 \<Longrightarrow> isnpolyh p n \<Longrightarrow> degree p = 0" |
|
52658 | 419 |
by (induct p arbitrary: n rule: degree.induct) auto |
33154 | 420 |
|
421 |
lemma degree_npolyhCN[simp]: "isnpolyh (CN c n p) n0 \<Longrightarrow> degree c = 0" |
|
422 |
using degree_isnpolyh_Suc by auto |
|
56009 | 423 |
|
33154 | 424 |
lemma degreen_npolyhCN[simp]: "isnpolyh (CN c n p) n0 \<Longrightarrow> degreen c n = 0" |
425 |
using degreen_0 by auto |
|
426 |
||
427 |
||
428 |
lemma degreen_polyadd: |
|
56009 | 429 |
assumes np: "isnpolyh p n0" |
430 |
and nq: "isnpolyh q n1" |
|
431 |
and m: "m \<le> max n0 n1" |
|
33154 | 432 |
shows "degreen (p +\<^sub>p q) m \<le> max (degreen p m) (degreen q m)" |
433 |
using np nq m |
|
434 |
proof (induct p q arbitrary: n0 n1 m rule: polyadd.induct) |
|
52803 | 435 |
case (2 c c' n' p' n0 n1) |
56009 | 436 |
then show ?case |
437 |
by (cases n') simp_all |
|
33154 | 438 |
next |
52803 | 439 |
case (3 c n p c' n0 n1) |
56009 | 440 |
then show ?case |
441 |
by (cases n) auto |
|
33154 | 442 |
next |
52803 | 443 |
case (4 c n p c' n' p' n0 n1 m) |
41763 | 444 |
have "n' = n \<or> n < n' \<or> n' < n" by arith |
56009 | 445 |
then show ?case |
41763 | 446 |
proof (elim disjE) |
447 |
assume [simp]: "n' = n" |
|
41812 | 448 |
from 4(4)[of n n m] 4(3)[of "Suc n" "Suc n" m] 4(5-7) |
41763 | 449 |
show ?thesis by (auto simp: Let_def) |
450 |
qed simp_all |
|
33154 | 451 |
qed auto |
452 |
||
56009 | 453 |
lemma polyadd_eq_const_degreen: |
454 |
assumes "isnpolyh p n0" |
|
455 |
and "isnpolyh q n1" |
|
456 |
and "polyadd p q = C c" |
|
457 |
shows "degreen p m = degreen q m" |
|
458 |
using assms |
|
33154 | 459 |
proof (induct p q arbitrary: m n0 n1 c rule: polyadd.induct) |
52803 | 460 |
case (4 c n p c' n' p' m n0 n1 x) |
56009 | 461 |
{ |
462 |
assume nn': "n' < n" |
|
463 |
then have ?case using 4 by simp |
|
464 |
} |
|
52803 | 465 |
moreover |
56009 | 466 |
{ |
467 |
assume nn': "\<not> n' < n" |
|
468 |
then have "n < n' \<or> n = n'" by arith |
|
52803 | 469 |
moreover { assume "n < n'" with 4 have ?case by simp } |
56009 | 470 |
moreover |
471 |
{ |
|
472 |
assume eq: "n = n'" |
|
473 |
then have ?case using 4 |
|
41763 | 474 |
apply (cases "p +\<^sub>p p' = 0\<^sub>p") |
475 |
apply (auto simp add: Let_def) |
|
52658 | 476 |
done |
52803 | 477 |
} |
56009 | 478 |
ultimately have ?case by blast |
479 |
} |
|
33154 | 480 |
ultimately show ?case by blast |
481 |
qed simp_all |
|
482 |
||
483 |
lemma polymul_properties: |
|
56000 | 484 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 485 |
and np: "isnpolyh p n0" |
486 |
and nq: "isnpolyh q n1" |
|
487 |
and m: "m \<le> min n0 n1" |
|
52803 | 488 |
shows "isnpolyh (p *\<^sub>p q) (min n0 n1)" |
56009 | 489 |
and "p *\<^sub>p q = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p \<or> q = 0\<^sub>p" |
490 |
and "degreen (p *\<^sub>p q) m = (if p = 0\<^sub>p \<or> q = 0\<^sub>p then 0 else degreen p m + degreen q m)" |
|
33154 | 491 |
using np nq m |
52658 | 492 |
proof (induct p q arbitrary: n0 n1 m rule: polymul.induct) |
52803 | 493 |
case (2 c c' n' p') |
56009 | 494 |
{ |
495 |
case (1 n0 n1) |
|
496 |
with "2.hyps"(4-6)[of n' n' n'] and "2.hyps"(1-3)[of "Suc n'" "Suc n'" n'] |
|
41811 | 497 |
show ?case by (auto simp add: min_def) |
33154 | 498 |
next |
56009 | 499 |
case (2 n0 n1) |
500 |
then show ?case by auto |
|
33154 | 501 |
next |
56009 | 502 |
case (3 n0 n1) |
503 |
then show ?case using "2.hyps" by auto |
|
504 |
} |
|
33154 | 505 |
next |
41813 | 506 |
case (3 c n p c') |
56009 | 507 |
{ |
508 |
case (1 n0 n1) |
|
509 |
with "3.hyps"(4-6)[of n n n] and "3.hyps"(1-3)[of "Suc n" "Suc n" n] |
|
41811 | 510 |
show ?case by (auto simp add: min_def) |
33154 | 511 |
next |
56009 | 512 |
case (2 n0 n1) |
513 |
then show ?case by auto |
|
33154 | 514 |
next |
56009 | 515 |
case (3 n0 n1) |
516 |
then show ?case using "3.hyps" by auto |
|
517 |
} |
|
33154 | 518 |
next |
519 |
case (4 c n p c' n' p') |
|
520 |
let ?cnp = "CN c n p" let ?cnp' = "CN c' n' p'" |
|
56009 | 521 |
{ |
522 |
case (1 n0 n1) |
|
523 |
then have cnp: "isnpolyh ?cnp n" |
|
524 |
and cnp': "isnpolyh ?cnp' n'" |
|
525 |
and np: "isnpolyh p n" |
|
526 |
and nc: "isnpolyh c (Suc n)" |
|
527 |
and np': "isnpolyh p' n'" |
|
528 |
and nc': "isnpolyh c' (Suc n')" |
|
529 |
and nn0: "n \<ge> n0" |
|
530 |
and nn1: "n' \<ge> n1" |
|
531 |
by simp_all |
|
41811 | 532 |
{ |
56009 | 533 |
assume "n < n'" |
534 |
with "4.hyps"(4-5)[OF np cnp', of n] and "4.hyps"(1)[OF nc cnp', of n] nn0 cnp |
|
535 |
have ?case by (simp add: min_def) |
|
536 |
} moreover { |
|
537 |
assume "n' < n" |
|
538 |
with "4.hyps"(16-17)[OF cnp np', of "n'"] and "4.hyps"(13)[OF cnp nc', of "Suc n'"] nn1 cnp' |
|
539 |
have ?case by (cases "Suc n' = n") (simp_all add: min_def) |
|
540 |
} moreover { |
|
541 |
assume "n' = n" |
|
542 |
with "4.hyps"(16-17)[OF cnp np', of n] and "4.hyps"(13)[OF cnp nc', of n] cnp cnp' nn1 nn0 |
|
543 |
have ?case |
|
544 |
apply (auto intro!: polyadd_normh) |
|
545 |
apply (simp_all add: min_def isnpolyh_mono[OF nn0]) |
|
546 |
done |
|
547 |
} |
|
548 |
ultimately show ?case by arith |
|
549 |
next |
|
550 |
fix n0 n1 m |
|
551 |
assume np: "isnpolyh ?cnp n0" |
|
552 |
assume np':"isnpolyh ?cnp' n1" |
|
553 |
assume m: "m \<le> min n0 n1" |
|
554 |
let ?d = "degreen (?cnp *\<^sub>p ?cnp') m" |
|
555 |
let ?d1 = "degreen ?cnp m" |
|
556 |
let ?d2 = "degreen ?cnp' m" |
|
557 |
let ?eq = "?d = (if ?cnp = 0\<^sub>p \<or> ?cnp' = 0\<^sub>p then 0 else ?d1 + ?d2)" |
|
56043 | 558 |
have "n' < n \<or> n < n' \<or> n' = n" by auto |
56009 | 559 |
moreover |
560 |
{ |
|
561 |
assume "n' < n \<or> n < n'" |
|
562 |
with "4.hyps"(3,6,18) np np' m have ?eq |
|
563 |
by auto |
|
564 |
} |
|
565 |
moreover |
|
566 |
{ |
|
567 |
assume nn': "n' = n" |
|
568 |
then have nn: "\<not> n' < n \<and> \<not> n < n'" by arith |
|
569 |
from "4.hyps"(16,18)[of n n' n] |
|
570 |
"4.hyps"(13,14)[of n "Suc n'" n] |
|
571 |
np np' nn' |
|
56043 | 572 |
have norm: |
573 |
"isnpolyh ?cnp n" |
|
574 |
"isnpolyh c' (Suc n)" |
|
575 |
"isnpolyh (?cnp *\<^sub>p c') n" |
|
576 |
"isnpolyh p' n" |
|
577 |
"isnpolyh (?cnp *\<^sub>p p') n" |
|
578 |
"isnpolyh (CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n" |
|
579 |
"?cnp *\<^sub>p c' = 0\<^sub>p \<longleftrightarrow> c' = 0\<^sub>p" |
|
580 |
"?cnp *\<^sub>p p' \<noteq> 0\<^sub>p" |
|
581 |
by (auto simp add: min_def) |
|
56009 | 582 |
{ |
583 |
assume mn: "m = n" |
|
584 |
from "4.hyps"(17,18)[OF norm(1,4), of n] |
|
585 |
"4.hyps"(13,15)[OF norm(1,2), of n] norm nn' mn |
|
586 |
have degs: |
|
587 |
"degreen (?cnp *\<^sub>p c') n = (if c' = 0\<^sub>p then 0 else ?d1 + degreen c' n)" |
|
588 |
"degreen (?cnp *\<^sub>p p') n = ?d1 + degreen p' n" |
|
589 |
by (simp_all add: min_def) |
|
590 |
from degs norm have th1: "degreen (?cnp *\<^sub>p c') n < degreen (CN 0\<^sub>p n (?cnp *\<^sub>p p')) n" |
|
591 |
by simp |
|
592 |
then have neq: "degreen (?cnp *\<^sub>p c') n \<noteq> degreen (CN 0\<^sub>p n (?cnp *\<^sub>p p')) n" |
|
593 |
by simp |
|
594 |
have nmin: "n \<le> min n n" |
|
595 |
by (simp add: min_def) |
|
596 |
from polyadd_different_degreen[OF norm(3,6) neq nmin] th1 |
|
597 |
have deg: "degreen (CN c n p *\<^sub>p c' +\<^sub>p CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n = |
|
598 |
degreen (CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n" |
|
599 |
by simp |
|
600 |
from "4.hyps"(16-18)[OF norm(1,4), of n] |
|
601 |
"4.hyps"(13-15)[OF norm(1,2), of n] |
|
602 |
mn norm m nn' deg |
|
603 |
have ?eq by simp |
|
41811 | 604 |
} |
33154 | 605 |
moreover |
56009 | 606 |
{ |
607 |
assume mn: "m \<noteq> n" |
|
608 |
then have mn': "m < n" |
|
609 |
using m np by auto |
|
610 |
from nn' m np have max1: "m \<le> max n n" |
|
611 |
by simp |
|
612 |
then have min1: "m \<le> min n n" |
|
613 |
by simp |
|
614 |
then have min2: "m \<le> min n (Suc n)" |
|
615 |
by simp |
|
616 |
from "4.hyps"(16-18)[OF norm(1,4) min1] |
|
617 |
"4.hyps"(13-15)[OF norm(1,2) min2] |
|
618 |
degreen_polyadd[OF norm(3,6) max1] |
|
619 |
have "degreen (?cnp *\<^sub>p c' +\<^sub>p CN 0\<^sub>p n (?cnp *\<^sub>p p')) m \<le> |
|
620 |
max (degreen (?cnp *\<^sub>p c') m) (degreen (CN 0\<^sub>p n (?cnp *\<^sub>p p')) m)" |
|
621 |
using mn nn' np np' by simp |
|
622 |
with "4.hyps"(16-18)[OF norm(1,4) min1] |
|
623 |
"4.hyps"(13-15)[OF norm(1,2) min2] |
|
624 |
degreen_0[OF norm(3) mn'] |
|
625 |
have ?eq using nn' mn np np' by clarsimp |
|
626 |
} |
|
627 |
ultimately have ?eq by blast |
|
628 |
} |
|
629 |
ultimately show ?eq by blast |
|
630 |
} |
|
631 |
{ |
|
632 |
case (2 n0 n1) |
|
633 |
then have np: "isnpolyh ?cnp n0" |
|
634 |
and np': "isnpolyh ?cnp' n1" |
|
56043 | 635 |
and m: "m \<le> min n0 n1" |
636 |
by simp_all |
|
56009 | 637 |
then have mn: "m \<le> n" by simp |
638 |
let ?c0p = "CN 0\<^sub>p n (?cnp *\<^sub>p p')" |
|
639 |
{ |
|
640 |
assume C: "?cnp *\<^sub>p c' +\<^sub>p ?c0p = 0\<^sub>p" "n' = n" |
|
641 |
then have nn: "\<not> n' < n \<and> \<not> n < n'" |
|
642 |
by simp |
|
643 |
from "4.hyps"(16-18) [of n n n] |
|
644 |
"4.hyps"(13-15)[of n "Suc n" n] |
|
645 |
np np' C(2) mn |
|
646 |
have norm: |
|
647 |
"isnpolyh ?cnp n" |
|
648 |
"isnpolyh c' (Suc n)" |
|
649 |
"isnpolyh (?cnp *\<^sub>p c') n" |
|
650 |
"isnpolyh p' n" |
|
651 |
"isnpolyh (?cnp *\<^sub>p p') n" |
|
652 |
"isnpolyh (CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n" |
|
653 |
"?cnp *\<^sub>p c' = 0\<^sub>p \<longleftrightarrow> c' = 0\<^sub>p" |
|
654 |
"?cnp *\<^sub>p p' \<noteq> 0\<^sub>p" |
|
655 |
"degreen (?cnp *\<^sub>p c') n = (if c' = 0\<^sub>p then 0 else degreen ?cnp n + degreen c' n)" |
|
656 |
"degreen (?cnp *\<^sub>p p') n = degreen ?cnp n + degreen p' n" |
|
657 |
by (simp_all add: min_def) |
|
658 |
from norm have cn: "isnpolyh (CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n" |
|
659 |
by simp |
|
660 |
have degneq: "degreen (?cnp *\<^sub>p c') n < degreen (CN 0\<^sub>p n (?cnp *\<^sub>p p')) n" |
|
661 |
using norm by simp |
|
662 |
from polyadd_eq_const_degreen[OF norm(3) cn C(1), where m="n"] degneq |
|
663 |
have False by simp |
|
664 |
} |
|
665 |
then show ?case using "4.hyps" by clarsimp |
|
666 |
} |
|
33154 | 667 |
qed auto |
668 |
||
56009 | 669 |
lemma polymul[simp]: "Ipoly bs (p *\<^sub>p q) = Ipoly bs p * Ipoly bs q" |
52658 | 670 |
by (induct p q rule: polymul.induct) (auto simp add: field_simps) |
33154 | 671 |
|
52803 | 672 |
lemma polymul_normh: |
56000 | 673 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56009 | 674 |
shows "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> isnpolyh (p *\<^sub>p q) (min n0 n1)" |
52803 | 675 |
using polymul_properties(1) by blast |
52658 | 676 |
|
52803 | 677 |
lemma polymul_eq0_iff: |
56000 | 678 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56009 | 679 |
shows "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> p *\<^sub>p q = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p \<or> q = 0\<^sub>p" |
52803 | 680 |
using polymul_properties(2) by blast |
52658 | 681 |
|
56207 | 682 |
lemma polymul_degreen: |
56000 | 683 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56009 | 684 |
shows "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> m \<le> min n0 n1 \<Longrightarrow> |
685 |
degreen (p *\<^sub>p q) m = (if p = 0\<^sub>p \<or> q = 0\<^sub>p then 0 else degreen p m + degreen q m)" |
|
56207 | 686 |
by (fact polymul_properties(3)) |
52658 | 687 |
|
52803 | 688 |
lemma polymul_norm: |
56000 | 689 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56009 | 690 |
shows "isnpoly p \<Longrightarrow> isnpoly q \<Longrightarrow> isnpoly (polymul p q)" |
33154 | 691 |
using polymul_normh[of "p" "0" "q" "0"] isnpoly_def by simp |
692 |
||
693 |
lemma headconst_zero: "isnpolyh p n0 \<Longrightarrow> headconst p = 0\<^sub>N \<longleftrightarrow> p = 0\<^sub>p" |
|
52658 | 694 |
by (induct p arbitrary: n0 rule: headconst.induct) auto |
33154 | 695 |
|
696 |
lemma headconst_isnormNum: "isnpolyh p n0 \<Longrightarrow> isnormNum (headconst p)" |
|
52658 | 697 |
by (induct p arbitrary: n0) auto |
33154 | 698 |
|
52658 | 699 |
lemma monic_eqI: |
52803 | 700 |
assumes np: "isnpolyh p n0" |
52658 | 701 |
shows "INum (headconst p) * Ipoly bs (fst (monic p)) = |
56000 | 702 |
(Ipoly bs p ::'a::{field_char_0,field_inverse_zero, power})" |
33154 | 703 |
unfolding monic_def Let_def |
52658 | 704 |
proof (cases "headconst p = 0\<^sub>N", simp_all add: headconst_zero[OF np]) |
33154 | 705 |
let ?h = "headconst p" |
706 |
assume pz: "p \<noteq> 0\<^sub>p" |
|
56000 | 707 |
{ |
708 |
assume hz: "INum ?h = (0::'a)" |
|
56043 | 709 |
from headconst_isnormNum[OF np] have norm: "isnormNum ?h" "isnormNum 0\<^sub>N" |
710 |
by simp_all |
|
711 |
from isnormNum_unique[where ?'a = 'a, OF norm] hz have "?h = 0\<^sub>N" |
|
712 |
by simp |
|
713 |
with headconst_zero[OF np] have "p = 0\<^sub>p" |
|
714 |
by blast |
|
715 |
with pz have False |
|
716 |
by blast |
|
717 |
} |
|
718 |
then show "INum (headconst p) = (0::'a) \<longrightarrow> \<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> = 0" |
|
719 |
by blast |
|
33154 | 720 |
qed |
721 |
||
722 |
||
41404 | 723 |
text{* polyneg is a negation and preserves normal forms *} |
33154 | 724 |
|
725 |
lemma polyneg[simp]: "Ipoly bs (polyneg p) = - Ipoly bs p" |
|
52658 | 726 |
by (induct p rule: polyneg.induct) auto |
33154 | 727 |
|
56009 | 728 |
lemma polyneg0: "isnpolyh p n \<Longrightarrow> (~\<^sub>p p) = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p" |
52658 | 729 |
by (induct p arbitrary: n rule: polyneg.induct) (auto simp add: Nneg_def) |
56009 | 730 |
|
33154 | 731 |
lemma polyneg_polyneg: "isnpolyh p n0 \<Longrightarrow> ~\<^sub>p (~\<^sub>p p) = p" |
52658 | 732 |
by (induct p arbitrary: n0 rule: polyneg.induct) auto |
56009 | 733 |
|
734 |
lemma polyneg_normh: "isnpolyh p n \<Longrightarrow> isnpolyh (polyneg p) n" |
|
735 |
by (induct p arbitrary: n rule: polyneg.induct) (auto simp add: polyneg0) |
|
33154 | 736 |
|
737 |
lemma polyneg_norm: "isnpoly p \<Longrightarrow> isnpoly (polyneg p)" |
|
738 |
using isnpoly_def polyneg_normh by simp |
|
739 |
||
740 |
||
41404 | 741 |
text{* polysub is a substraction and preserves normal forms *} |
742 |
||
56009 | 743 |
lemma polysub[simp]: "Ipoly bs (polysub p q) = Ipoly bs p - Ipoly bs q" |
52658 | 744 |
by (simp add: polysub_def) |
56009 | 745 |
|
746 |
lemma polysub_normh: "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> isnpolyh (polysub p q) (min n0 n1)" |
|
52658 | 747 |
by (simp add: polysub_def polyneg_normh polyadd_normh) |
33154 | 748 |
|
56009 | 749 |
lemma polysub_norm: "isnpoly p \<Longrightarrow> isnpoly q \<Longrightarrow> isnpoly (polysub p q)" |
52803 | 750 |
using polyadd_norm polyneg_norm by (simp add: polysub_def) |
56009 | 751 |
|
52658 | 752 |
lemma polysub_same_0[simp]: |
56000 | 753 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
41814 | 754 |
shows "isnpolyh p n0 \<Longrightarrow> polysub p p = 0\<^sub>p" |
52658 | 755 |
unfolding polysub_def split_def fst_conv snd_conv |
756 |
by (induct p arbitrary: n0) (auto simp add: Let_def Nsub0[simplified Nsub_def]) |
|
33154 | 757 |
|
52803 | 758 |
lemma polysub_0: |
56000 | 759 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56009 | 760 |
shows "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> p -\<^sub>p q = 0\<^sub>p \<longleftrightarrow> p = q" |
33154 | 761 |
unfolding polysub_def split_def fst_conv snd_conv |
41763 | 762 |
by (induct p q arbitrary: n0 n1 rule:polyadd.induct) |
52658 | 763 |
(auto simp: Nsub0[simplified Nsub_def] Let_def) |
33154 | 764 |
|
765 |
text{* polypow is a power function and preserves normal forms *} |
|
41404 | 766 |
|
56009 | 767 |
lemma polypow[simp]: |
768 |
"Ipoly bs (polypow n p) = (Ipoly bs p :: 'a::{field_char_0,field_inverse_zero}) ^ n" |
|
52658 | 769 |
proof (induct n rule: polypow.induct) |
770 |
case 1 |
|
56043 | 771 |
then show ?case |
772 |
by simp |
|
33154 | 773 |
next |
774 |
case (2 n) |
|
775 |
let ?q = "polypow ((Suc n) div 2) p" |
|
41813 | 776 |
let ?d = "polymul ?q ?q" |
56043 | 777 |
have "odd (Suc n) \<or> even (Suc n)" |
778 |
by simp |
|
52803 | 779 |
moreover |
56043 | 780 |
{ |
781 |
assume odd: "odd (Suc n)" |
|
56000 | 782 |
have th: "(Suc (Suc (Suc 0) * (Suc n div Suc (Suc 0)))) = Suc n div 2 + Suc n div 2 + 1" |
52658 | 783 |
by arith |
56043 | 784 |
from odd have "Ipoly bs (p ^\<^sub>p Suc n) = Ipoly bs (polymul p ?d)" |
785 |
by (simp add: Let_def) |
|
786 |
also have "\<dots> = (Ipoly bs p) * (Ipoly bs p)^(Suc n div 2) * (Ipoly bs p)^(Suc n div 2)" |
|
33154 | 787 |
using "2.hyps" by simp |
788 |
also have "\<dots> = (Ipoly bs p) ^ (Suc n div 2 + Suc n div 2 + 1)" |
|
52658 | 789 |
by (simp only: power_add power_one_right) simp |
56000 | 790 |
also have "\<dots> = (Ipoly bs p) ^ (Suc (Suc (Suc 0) * (Suc n div Suc (Suc 0))))" |
33154 | 791 |
by (simp only: th) |
52803 | 792 |
finally have ?case |
56043 | 793 |
using odd_nat_div_two_times_two_plus_one[OF odd, symmetric] by simp |
794 |
} |
|
52803 | 795 |
moreover |
56043 | 796 |
{ |
797 |
assume even: "even (Suc n)" |
|
56000 | 798 |
have th: "(Suc (Suc 0)) * (Suc n div Suc (Suc 0)) = Suc n div 2 + Suc n div 2" |
52658 | 799 |
by arith |
56043 | 800 |
from even have "Ipoly bs (p ^\<^sub>p Suc n) = Ipoly bs ?d" |
801 |
by (simp add: Let_def) |
|
33154 | 802 |
also have "\<dots> = (Ipoly bs p) ^ (Suc n div 2 + Suc n div 2)" |
56043 | 803 |
using "2.hyps" by (simp only: power_add) simp |
804 |
finally have ?case using even_nat_div_two_times_two[OF even] |
|
805 |
by (simp only: th) |
|
806 |
} |
|
33154 | 807 |
ultimately show ?case by blast |
808 |
qed |
|
809 |
||
52803 | 810 |
lemma polypow_normh: |
56000 | 811 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
33154 | 812 |
shows "isnpolyh p n \<Longrightarrow> isnpolyh (polypow k p) n" |
813 |
proof (induct k arbitrary: n rule: polypow.induct) |
|
56043 | 814 |
case 1 |
815 |
then show ?case by auto |
|
816 |
next |
|
33154 | 817 |
case (2 k n) |
818 |
let ?q = "polypow (Suc k div 2) p" |
|
41813 | 819 |
let ?d = "polymul ?q ?q" |
56043 | 820 |
from 2 have th1: "isnpolyh ?q n" and th2: "isnpolyh p n" |
821 |
by blast+ |
|
822 |
from polymul_normh[OF th1 th1] have dn: "isnpolyh ?d n" |
|
823 |
by simp |
|
824 |
from polymul_normh[OF th2 dn] have on: "isnpolyh (polymul p ?d) n" |
|
825 |
by simp |
|
826 |
from dn on show ?case |
|
827 |
by (simp add: Let_def) |
|
828 |
qed |
|
33154 | 829 |
|
52803 | 830 |
lemma polypow_norm: |
56000 | 831 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
33154 | 832 |
shows "isnpoly p \<Longrightarrow> isnpoly (polypow k p)" |
833 |
by (simp add: polypow_normh isnpoly_def) |
|
834 |
||
41404 | 835 |
text{* Finally the whole normalization *} |
33154 | 836 |
|
52658 | 837 |
lemma polynate [simp]: |
56000 | 838 |
"Ipoly bs (polynate p) = (Ipoly bs p :: 'a ::{field_char_0,field_inverse_zero})" |
52658 | 839 |
by (induct p rule:polynate.induct) auto |
33154 | 840 |
|
52803 | 841 |
lemma polynate_norm[simp]: |
56000 | 842 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
33154 | 843 |
shows "isnpoly (polynate p)" |
52658 | 844 |
by (induct p rule: polynate.induct) |
845 |
(simp_all add: polyadd_norm polymul_norm polysub_norm polyneg_norm polypow_norm, |
|
846 |
simp_all add: isnpoly_def) |
|
33154 | 847 |
|
848 |
text{* shift1 *} |
|
849 |
||
850 |
||
851 |
lemma shift1: "Ipoly bs (shift1 p) = Ipoly bs (Mul (Bound 0) p)" |
|
52658 | 852 |
by (simp add: shift1_def) |
33154 | 853 |
|
52803 | 854 |
lemma shift1_isnpoly: |
56207 | 855 |
assumes "isnpoly p" |
856 |
and "p \<noteq> 0\<^sub>p" |
|
52658 | 857 |
shows "isnpoly (shift1 p) " |
56207 | 858 |
using assms by (simp add: shift1_def isnpoly_def) |
33154 | 859 |
|
860 |
lemma shift1_nz[simp]:"shift1 p \<noteq> 0\<^sub>p" |
|
861 |
by (simp add: shift1_def) |
|
56043 | 862 |
|
863 |
lemma funpow_shift1_isnpoly: "isnpoly p \<Longrightarrow> p \<noteq> 0\<^sub>p \<Longrightarrow> isnpoly (funpow n shift1 p)" |
|
39246 | 864 |
by (induct n arbitrary: p) (auto simp add: shift1_isnpoly funpow_swap1) |
33154 | 865 |
|
52803 | 866 |
lemma funpow_isnpolyh: |
56207 | 867 |
assumes "\<And>p. isnpolyh p n \<Longrightarrow> isnpolyh (f p) n" |
868 |
and "isnpolyh p n" |
|
33154 | 869 |
shows "isnpolyh (funpow k f p) n" |
56207 | 870 |
using assms by (induct k arbitrary: p) auto |
33154 | 871 |
|
52658 | 872 |
lemma funpow_shift1: |
56000 | 873 |
"(Ipoly bs (funpow n shift1 p) :: 'a :: {field_char_0,field_inverse_zero}) = |
52658 | 874 |
Ipoly bs (Mul (Pw (Bound 0) n) p)" |
875 |
by (induct n arbitrary: p) (simp_all add: shift1_isnpoly shift1) |
|
33154 | 876 |
|
56043 | 877 |
lemma shift1_isnpolyh: "isnpolyh p n0 \<Longrightarrow> p \<noteq> 0\<^sub>p \<Longrightarrow> isnpolyh (shift1 p) 0" |
33154 | 878 |
using isnpolyh_mono[where n="n0" and n'="0" and p="p"] by (simp add: shift1_def) |
879 |
||
52803 | 880 |
lemma funpow_shift1_1: |
56000 | 881 |
"(Ipoly bs (funpow n shift1 p) :: 'a :: {field_char_0,field_inverse_zero}) = |
52658 | 882 |
Ipoly bs (funpow n shift1 (1)\<^sub>p *\<^sub>p p)" |
33154 | 883 |
by (simp add: funpow_shift1) |
884 |
||
885 |
lemma poly_cmul[simp]: "Ipoly bs (poly_cmul c p) = Ipoly bs (Mul (C c) p)" |
|
45129
1fce03e3e8ad
tuned proofs -- eliminated vacuous "induct arbitrary: ..." situations;
wenzelm
parents:
41842
diff
changeset
|
886 |
by (induct p rule: poly_cmul.induct) (auto simp add: field_simps) |
33154 | 887 |
|
888 |
lemma behead: |
|
56207 | 889 |
assumes "isnpolyh p n" |
52658 | 890 |
shows "Ipoly bs (Add (Mul (head p) (Pw (Bound 0) (degree p))) (behead p)) = |
56000 | 891 |
(Ipoly bs p :: 'a :: {field_char_0,field_inverse_zero})" |
56207 | 892 |
using assms |
33154 | 893 |
proof (induct p arbitrary: n rule: behead.induct) |
56009 | 894 |
case (1 c p n) |
895 |
then have pn: "isnpolyh p n" by simp |
|
52803 | 896 |
from 1(1)[OF pn] |
897 |
have th:"Ipoly bs (Add (Mul (head p) (Pw (Bound 0) (degree p))) (behead p)) = Ipoly bs p" . |
|
52658 | 898 |
then show ?case using "1.hyps" |
899 |
apply (simp add: Let_def,cases "behead p = 0\<^sub>p") |
|
900 |
apply (simp_all add: th[symmetric] field_simps) |
|
901 |
done |
|
33154 | 902 |
qed (auto simp add: Let_def) |
903 |
||
904 |
lemma behead_isnpolyh: |
|
56207 | 905 |
assumes "isnpolyh p n" |
52658 | 906 |
shows "isnpolyh (behead p) n" |
56207 | 907 |
using assms by (induct p rule: behead.induct) (auto simp add: Let_def isnpolyh_mono) |
52658 | 908 |
|
33154 | 909 |
|
56207 | 910 |
subsection {* Miscellaneous lemmas about indexes, decrementation, substitution etc ... *} |
52658 | 911 |
|
33154 | 912 |
lemma isnpolyh_polybound0: "isnpolyh p (Suc n) \<Longrightarrow> polybound0 p" |
52658 | 913 |
proof (induct p arbitrary: n rule: poly.induct, auto) |
33154 | 914 |
case (goal1 c n p n') |
56009 | 915 |
then have "n = Suc (n - 1)" |
916 |
by simp |
|
917 |
then have "isnpolyh p (Suc (n - 1))" |
|
918 |
using `isnpolyh p n` by simp |
|
919 |
with goal1(2) show ?case |
|
920 |
by simp |
|
33154 | 921 |
qed |
922 |
||
923 |
lemma isconstant_polybound0: "isnpolyh p n0 \<Longrightarrow> isconstant p \<longleftrightarrow> polybound0 p" |
|
52658 | 924 |
by (induct p arbitrary: n0 rule: isconstant.induct) (auto simp add: isnpolyh_polybound0) |
33154 | 925 |
|
52658 | 926 |
lemma decrpoly_zero[simp]: "decrpoly p = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p" |
927 |
by (induct p) auto |
|
33154 | 928 |
|
929 |
lemma decrpoly_normh: "isnpolyh p n0 \<Longrightarrow> polybound0 p \<Longrightarrow> isnpolyh (decrpoly p) (n0 - 1)" |
|
52658 | 930 |
apply (induct p arbitrary: n0) |
931 |
apply auto |
|
56043 | 932 |
apply atomize |
58259 | 933 |
apply (rename_tac nat a b, erule_tac x = "Suc nat" in allE) |
33154 | 934 |
apply auto |
935 |
done |
|
936 |
||
937 |
lemma head_polybound0: "isnpolyh p n0 \<Longrightarrow> polybound0 (head p)" |
|
52658 | 938 |
by (induct p arbitrary: n0 rule: head.induct) (auto intro: isnpolyh_polybound0) |
33154 | 939 |
|
940 |
lemma polybound0_I: |
|
56207 | 941 |
assumes "polybound0 a" |
56009 | 942 |
shows "Ipoly (b # bs) a = Ipoly (b' # bs) a" |
56207 | 943 |
using assms by (induct a rule: poly.induct) auto |
52658 | 944 |
|
56009 | 945 |
lemma polysubst0_I: "Ipoly (b # bs) (polysubst0 a t) = Ipoly ((Ipoly (b # bs) a) # bs) t" |
33154 | 946 |
by (induct t) simp_all |
947 |
||
948 |
lemma polysubst0_I': |
|
56207 | 949 |
assumes "polybound0 a" |
56009 | 950 |
shows "Ipoly (b # bs) (polysubst0 a t) = Ipoly ((Ipoly (b' # bs) a) # bs) t" |
56207 | 951 |
by (induct t) (simp_all add: polybound0_I[OF assms, where b="b" and b'="b'"]) |
33154 | 952 |
|
52658 | 953 |
lemma decrpoly: |
56207 | 954 |
assumes "polybound0 t" |
56043 | 955 |
shows "Ipoly (x # bs) t = Ipoly bs (decrpoly t)" |
56207 | 956 |
using assms by (induct t rule: decrpoly.induct) simp_all |
33154 | 957 |
|
52658 | 958 |
lemma polysubst0_polybound0: |
56207 | 959 |
assumes "polybound0 t" |
33154 | 960 |
shows "polybound0 (polysubst0 t a)" |
56207 | 961 |
using assms by (induct a rule: poly.induct) auto |
33154 | 962 |
|
963 |
lemma degree0_polybound0: "isnpolyh p n \<Longrightarrow> degree p = 0 \<Longrightarrow> polybound0 p" |
|
52658 | 964 |
by (induct p arbitrary: n rule: degree.induct) (auto simp add: isnpolyh_polybound0) |
33154 | 965 |
|
56043 | 966 |
primrec maxindex :: "poly \<Rightarrow> nat" |
967 |
where |
|
33154 | 968 |
"maxindex (Bound n) = n + 1" |
969 |
| "maxindex (CN c n p) = max (n + 1) (max (maxindex c) (maxindex p))" |
|
970 |
| "maxindex (Add p q) = max (maxindex p) (maxindex q)" |
|
971 |
| "maxindex (Sub p q) = max (maxindex p) (maxindex q)" |
|
972 |
| "maxindex (Mul p q) = max (maxindex p) (maxindex q)" |
|
973 |
| "maxindex (Neg p) = maxindex p" |
|
974 |
| "maxindex (Pw p n) = maxindex p" |
|
975 |
| "maxindex (C x) = 0" |
|
976 |
||
52658 | 977 |
definition wf_bs :: "'a list \<Rightarrow> poly \<Rightarrow> bool" |
56000 | 978 |
where "wf_bs bs p \<longleftrightarrow> length bs \<ge> maxindex p" |
33154 | 979 |
|
56043 | 980 |
lemma wf_bs_coefficients: "wf_bs bs p \<Longrightarrow> \<forall>c \<in> set (coefficients p). wf_bs bs c" |
52658 | 981 |
proof (induct p rule: coefficients.induct) |
52803 | 982 |
case (1 c p) |
983 |
show ?case |
|
33154 | 984 |
proof |
56009 | 985 |
fix x |
986 |
assume xc: "x \<in> set (coefficients (CN c 0 p))" |
|
987 |
then have "x = c \<or> x \<in> set (coefficients p)" |
|
988 |
by simp |
|
52803 | 989 |
moreover |
56009 | 990 |
{ |
991 |
assume "x = c" |
|
992 |
then have "wf_bs bs x" |
|
56043 | 993 |
using "1.prems" unfolding wf_bs_def by simp |
56009 | 994 |
} |
995 |
moreover |
|
996 |
{ |
|
997 |
assume H: "x \<in> set (coefficients p)" |
|
998 |
from "1.prems" have "wf_bs bs p" |
|
999 |
unfolding wf_bs_def by simp |
|
1000 |
with "1.hyps" H have "wf_bs bs x" |
|
1001 |
by blast |
|
1002 |
} |
|
56066 | 1003 |
ultimately show "wf_bs bs x" |
56009 | 1004 |
by blast |
33154 | 1005 |
qed |
1006 |
qed simp_all |
|
1007 |
||
56043 | 1008 |
lemma maxindex_coefficients: "\<forall>c \<in> set (coefficients p). maxindex c \<le> maxindex p" |
52658 | 1009 |
by (induct p rule: coefficients.induct) auto |
33154 | 1010 |
|
56000 | 1011 |
lemma wf_bs_I: "wf_bs bs p \<Longrightarrow> Ipoly (bs @ bs') p = Ipoly bs p" |
52658 | 1012 |
unfolding wf_bs_def by (induct p) (auto simp add: nth_append) |
33154 | 1013 |
|
52658 | 1014 |
lemma take_maxindex_wf: |
52803 | 1015 |
assumes wf: "wf_bs bs p" |
33154 | 1016 |
shows "Ipoly (take (maxindex p) bs) p = Ipoly bs p" |
56009 | 1017 |
proof - |
33154 | 1018 |
let ?ip = "maxindex p" |
1019 |
let ?tbs = "take ?ip bs" |
|
56009 | 1020 |
from wf have "length ?tbs = ?ip" |
1021 |
unfolding wf_bs_def by simp |
|
1022 |
then have wf': "wf_bs ?tbs p" |
|
1023 |
unfolding wf_bs_def by simp |
|
56043 | 1024 |
have eq: "bs = ?tbs @ drop ?ip bs" |
56009 | 1025 |
by simp |
1026 |
from wf_bs_I[OF wf', of "drop ?ip bs"] show ?thesis |
|
1027 |
using eq by simp |
|
33154 | 1028 |
qed |
1029 |
||
1030 |
lemma decr_maxindex: "polybound0 p \<Longrightarrow> maxindex (decrpoly p) = maxindex p - 1" |
|
52658 | 1031 |
by (induct p) auto |
33154 | 1032 |
|
1033 |
lemma wf_bs_insensitive: "length bs = length bs' \<Longrightarrow> wf_bs bs p = wf_bs bs' p" |
|
1034 |
unfolding wf_bs_def by simp |
|
1035 |
||
56207 | 1036 |
lemma wf_bs_insensitive': "wf_bs (x # bs) p = wf_bs (y # bs) p" |
33154 | 1037 |
unfolding wf_bs_def by simp |
1038 |
||
56207 | 1039 |
lemma wf_bs_coefficients': "\<forall>c \<in> set (coefficients p). wf_bs bs c \<Longrightarrow> wf_bs (x # bs) p" |
52658 | 1040 |
by (induct p rule: coefficients.induct) (auto simp add: wf_bs_def) |
56043 | 1041 |
|
33154 | 1042 |
lemma coefficients_Nil[simp]: "coefficients p \<noteq> []" |
52658 | 1043 |
by (induct p rule: coefficients.induct) simp_all |
33154 | 1044 |
|
1045 |
lemma coefficients_head: "last (coefficients p) = head p" |
|
52658 | 1046 |
by (induct p rule: coefficients.induct) auto |
33154 | 1047 |
|
56207 | 1048 |
lemma wf_bs_decrpoly: "wf_bs bs (decrpoly p) \<Longrightarrow> wf_bs (x # bs) p" |
52658 | 1049 |
unfolding wf_bs_def by (induct p rule: decrpoly.induct) auto |
33154 | 1050 |
|
56043 | 1051 |
lemma length_le_list_ex: "length xs \<le> n \<Longrightarrow> \<exists>ys. length (xs @ ys) = n" |
56207 | 1052 |
apply (rule exI[where x="replicate (n - length xs) z" for z]) |
52658 | 1053 |
apply simp |
1054 |
done |
|
1055 |
||
56043 | 1056 |
lemma isnpolyh_Suc_const: "isnpolyh p (Suc n) \<Longrightarrow> isconstant p" |
52658 | 1057 |
apply (cases p) |
1058 |
apply auto |
|
58259 | 1059 |
apply (rename_tac nat a, case_tac "nat") |
52658 | 1060 |
apply simp_all |
1061 |
done |
|
33154 | 1062 |
|
1063 |
lemma wf_bs_polyadd: "wf_bs bs p \<and> wf_bs bs q \<longrightarrow> wf_bs bs (p +\<^sub>p q)" |
|
56066 | 1064 |
unfolding wf_bs_def by (induct p q rule: polyadd.induct) (auto simp add: Let_def) |
33154 | 1065 |
|
1066 |
lemma wf_bs_polyul: "wf_bs bs p \<Longrightarrow> wf_bs bs q \<Longrightarrow> wf_bs bs (p *\<^sub>p q)" |
|
52803 | 1067 |
unfolding wf_bs_def |
1068 |
apply (induct p q arbitrary: bs rule: polymul.induct) |
|
33154 | 1069 |
apply (simp_all add: wf_bs_polyadd) |
1070 |
apply clarsimp |
|
1071 |
apply (rule wf_bs_polyadd[unfolded wf_bs_def, rule_format]) |
|
1072 |
apply auto |
|
1073 |
done |
|
1074 |
||
1075 |
lemma wf_bs_polyneg: "wf_bs bs p \<Longrightarrow> wf_bs bs (~\<^sub>p p)" |
|
52658 | 1076 |
unfolding wf_bs_def by (induct p rule: polyneg.induct) auto |
33154 | 1077 |
|
1078 |
lemma wf_bs_polysub: "wf_bs bs p \<Longrightarrow> wf_bs bs q \<Longrightarrow> wf_bs bs (p -\<^sub>p q)" |
|
56043 | 1079 |
unfolding polysub_def split_def fst_conv snd_conv |
1080 |
using wf_bs_polyadd wf_bs_polyneg by blast |
|
33154 | 1081 |
|
52658 | 1082 |
|
56043 | 1083 |
subsection {* Canonicity of polynomial representation, see lemma isnpolyh_unique *} |
33154 | 1084 |
|
1085 |
definition "polypoly bs p = map (Ipoly bs) (coefficients p)" |
|
56043 | 1086 |
definition "polypoly' bs p = map (Ipoly bs \<circ> decrpoly) (coefficients p)" |
1087 |
definition "poly_nate bs p = map (Ipoly bs \<circ> decrpoly) (coefficients (polynate p))" |
|
33154 | 1088 |
|
56043 | 1089 |
lemma coefficients_normh: "isnpolyh p n0 \<Longrightarrow> \<forall>q \<in> set (coefficients p). isnpolyh q n0" |
33154 | 1090 |
proof (induct p arbitrary: n0 rule: coefficients.induct) |
1091 |
case (1 c p n0) |
|
56009 | 1092 |
have cp: "isnpolyh (CN c 0 p) n0" |
1093 |
by fact |
|
1094 |
then have norm: "isnpolyh c 0" "isnpolyh p 0" "p \<noteq> 0\<^sub>p" "n0 = 0" |
|
33154 | 1095 |
by (auto simp add: isnpolyh_mono[where n'=0]) |
56009 | 1096 |
from "1.hyps"[OF norm(2)] norm(1) norm(4) show ?case |
1097 |
by simp |
|
33154 | 1098 |
qed auto |
1099 |
||
56043 | 1100 |
lemma coefficients_isconst: "isnpolyh p n \<Longrightarrow> \<forall>q \<in> set (coefficients p). isconstant q" |
1101 |
by (induct p arbitrary: n rule: coefficients.induct) (auto simp add: isnpolyh_Suc_const) |
|
33154 | 1102 |
|
1103 |
lemma polypoly_polypoly': |
|
1104 |
assumes np: "isnpolyh p n0" |
|
56043 | 1105 |
shows "polypoly (x # bs) p = polypoly' bs p" |
1106 |
proof - |
|
33154 | 1107 |
let ?cf = "set (coefficients p)" |
1108 |
from coefficients_normh[OF np] have cn_norm: "\<forall> q\<in> ?cf. isnpolyh q n0" . |
|
56043 | 1109 |
{ |
1110 |
fix q |
|
1111 |
assume q: "q \<in> ?cf" |
|
1112 |
from q cn_norm have th: "isnpolyh q n0" |
|
1113 |
by blast |
|
1114 |
from coefficients_isconst[OF np] q have "isconstant q" |
|
1115 |
by blast |
|
1116 |
with isconstant_polybound0[OF th] have "polybound0 q" |
|
1117 |
by blast |
|
1118 |
} |
|
56009 | 1119 |
then have "\<forall>q \<in> ?cf. polybound0 q" .. |
56043 | 1120 |
then have "\<forall>q \<in> ?cf. Ipoly (x # bs) q = Ipoly bs (decrpoly q)" |
33154 | 1121 |
using polybound0_I[where b=x and bs=bs and b'=y] decrpoly[where x=x and bs=bs] |
1122 |
by auto |
|
56043 | 1123 |
then show ?thesis |
1124 |
unfolding polypoly_def polypoly'_def by simp |
|
33154 | 1125 |
qed |
1126 |
||
1127 |
lemma polypoly_poly: |
|
56043 | 1128 |
assumes "isnpolyh p n0" |
1129 |
shows "Ipoly (x # bs) p = poly (polypoly (x # bs) p) x" |
|
1130 |
using assms |
|
52658 | 1131 |
by (induct p arbitrary: n0 bs rule: coefficients.induct) (auto simp add: polypoly_def) |
33154 | 1132 |
|
52803 | 1133 |
lemma polypoly'_poly: |
56043 | 1134 |
assumes "isnpolyh p n0" |
52658 | 1135 |
shows "\<lparr>p\<rparr>\<^sub>p\<^bsup>x # bs\<^esup> = poly (polypoly' bs p) x" |
56043 | 1136 |
using polypoly_poly[OF assms, simplified polypoly_polypoly'[OF assms]] . |
33154 | 1137 |
|
1138 |
||
1139 |
lemma polypoly_poly_polybound0: |
|
56043 | 1140 |
assumes "isnpolyh p n0" |
1141 |
and "polybound0 p" |
|
33154 | 1142 |
shows "polypoly bs p = [Ipoly bs p]" |
56043 | 1143 |
using assms |
1144 |
unfolding polypoly_def |
|
52658 | 1145 |
apply (cases p) |
1146 |
apply auto |
|
58259 | 1147 |
apply (rename_tac nat a, case_tac nat) |
52658 | 1148 |
apply auto |
1149 |
done |
|
33154 | 1150 |
|
52803 | 1151 |
lemma head_isnpolyh: "isnpolyh p n0 \<Longrightarrow> isnpolyh (head p) n0" |
52658 | 1152 |
by (induct p rule: head.induct) auto |
33154 | 1153 |
|
56043 | 1154 |
lemma headn_nz[simp]: "isnpolyh p n0 \<Longrightarrow> headn p m = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p" |
52658 | 1155 |
by (cases p) auto |
33154 | 1156 |
|
1157 |
lemma head_eq_headn0: "head p = headn p 0" |
|
52658 | 1158 |
by (induct p rule: head.induct) simp_all |
33154 | 1159 |
|
56043 | 1160 |
lemma head_nz[simp]: "isnpolyh p n0 \<Longrightarrow> head p = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p" |
33154 | 1161 |
by (simp add: head_eq_headn0) |
1162 |
||
52803 | 1163 |
lemma isnpolyh_zero_iff: |
52658 | 1164 |
assumes nq: "isnpolyh p n0" |
56000 | 1165 |
and eq :"\<forall>bs. wf_bs bs p \<longrightarrow> \<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> = (0::'a::{field_char_0,field_inverse_zero, power})" |
33154 | 1166 |
shows "p = 0\<^sub>p" |
52658 | 1167 |
using nq eq |
34915 | 1168 |
proof (induct "maxindex p" arbitrary: p n0 rule: less_induct) |
1169 |
case less |
|
1170 |
note np = `isnpolyh p n0` and zp = `\<forall>bs. wf_bs bs p \<longrightarrow> \<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> = (0::'a)` |
|
56000 | 1171 |
{ |
1172 |
assume nz: "maxindex p = 0" |
|
1173 |
then obtain c where "p = C c" |
|
1174 |
using np by (cases p) auto |
|
1175 |
with zp np have "p = 0\<^sub>p" |
|
1176 |
unfolding wf_bs_def by simp |
|
1177 |
} |
|
33154 | 1178 |
moreover |
56000 | 1179 |
{ |
1180 |
assume nz: "maxindex p \<noteq> 0" |
|
33154 | 1181 |
let ?h = "head p" |
1182 |
let ?hd = "decrpoly ?h" |
|
1183 |
let ?ihd = "maxindex ?hd" |
|
56000 | 1184 |
from head_isnpolyh[OF np] head_polybound0[OF np] |
1185 |
have h: "isnpolyh ?h n0" "polybound0 ?h" |
|
33154 | 1186 |
by simp_all |
56000 | 1187 |
then have nhd: "isnpolyh ?hd (n0 - 1)" |
1188 |
using decrpoly_normh by blast |
|
52803 | 1189 |
|
33154 | 1190 |
from maxindex_coefficients[of p] coefficients_head[of p, symmetric] |
56000 | 1191 |
have mihn: "maxindex ?h \<le> maxindex p" |
1192 |
by auto |
|
1193 |
with decr_maxindex[OF h(2)] nz have ihd_lt_n: "?ihd < maxindex p" |
|
1194 |
by auto |
|
1195 |
{ |
|
1196 |
fix bs :: "'a list" |
|
1197 |
assume bs: "wf_bs bs ?hd" |
|
33154 | 1198 |
let ?ts = "take ?ihd bs" |
1199 |
let ?rs = "drop ?ihd bs" |
|
56000 | 1200 |
have ts: "wf_bs ?ts ?hd" |
1201 |
using bs unfolding wf_bs_def by simp |
|
1202 |
have bs_ts_eq: "?ts @ ?rs = bs" |
|
1203 |
by simp |
|
1204 |
from wf_bs_decrpoly[OF ts] have tsh: " \<forall>x. wf_bs (x # ?ts) ?h" |
|
1205 |
by simp |
|
1206 |
from ihd_lt_n have "\<forall>x. length (x # ?ts) \<le> maxindex p" |
|
1207 |
by simp |
|
1208 |
with length_le_list_ex obtain xs where xs: "length ((x # ?ts) @ xs) = maxindex p" |
|
1209 |
by blast |
|
1210 |
then have "\<forall>x. wf_bs ((x # ?ts) @ xs) p" |
|
1211 |
unfolding wf_bs_def by simp |
|
1212 |
with zp have "\<forall>x. Ipoly ((x # ?ts) @ xs) p = 0" |
|
1213 |
by blast |
|
1214 |
then have "\<forall>x. Ipoly (x # (?ts @ xs)) p = 0" |
|
1215 |
by simp |
|
33154 | 1216 |
with polypoly_poly[OF np, where ?'a = 'a] polypoly_polypoly'[OF np, where ?'a = 'a] |
56000 | 1217 |
have "\<forall>x. poly (polypoly' (?ts @ xs) p) x = poly [] x" |
1218 |
by simp |
|
1219 |
then have "poly (polypoly' (?ts @ xs) p) = poly []" |
|
1220 |
by auto |
|
1221 |
then have "\<forall>c \<in> set (coefficients p). Ipoly (?ts @ xs) (decrpoly c) = 0" |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1222 |
using poly_zero[where ?'a='a] by (simp add: polypoly'_def list_all_iff) |
33154 | 1223 |
with coefficients_head[of p, symmetric] |
56000 | 1224 |
have th0: "Ipoly (?ts @ xs) ?hd = 0" |
1225 |
by simp |
|
1226 |
from bs have wf'': "wf_bs ?ts ?hd" |
|
1227 |
unfolding wf_bs_def by simp |
|
1228 |
with th0 wf_bs_I[of ?ts ?hd xs] have "Ipoly ?ts ?hd = 0" |
|
1229 |
by simp |
|
1230 |
with wf'' wf_bs_I[of ?ts ?hd ?rs] bs_ts_eq have "\<lparr>?hd\<rparr>\<^sub>p\<^bsup>bs\<^esup> = 0" |
|
1231 |
by simp |
|
1232 |
} |
|
1233 |
then have hdz: "\<forall>bs. wf_bs bs ?hd \<longrightarrow> \<lparr>?hd\<rparr>\<^sub>p\<^bsup>bs\<^esup> = (0::'a)" |
|
1234 |
by blast |
|
1235 |
from less(1)[OF ihd_lt_n nhd] hdz have "?hd = 0\<^sub>p" |
|
1236 |
by blast |
|
1237 |
then have "?h = 0\<^sub>p" by simp |
|
1238 |
with head_nz[OF np] have "p = 0\<^sub>p" by simp |
|
1239 |
} |
|
1240 |
ultimately show "p = 0\<^sub>p" |
|
1241 |
by blast |
|
33154 | 1242 |
qed |
1243 |
||
52803 | 1244 |
lemma isnpolyh_unique: |
56000 | 1245 |
assumes np: "isnpolyh p n0" |
52658 | 1246 |
and nq: "isnpolyh q n1" |
56000 | 1247 |
shows "(\<forall>bs. \<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> = (\<lparr>q\<rparr>\<^sub>p\<^bsup>bs\<^esup> :: 'a::{field_char_0,field_inverse_zero,power})) \<longleftrightarrow> p = q" |
1248 |
proof auto |
|
1249 |
assume H: "\<forall>bs. (\<lparr>p\<rparr>\<^sub>p\<^bsup>bs\<^esup> ::'a) = \<lparr>q\<rparr>\<^sub>p\<^bsup>bs\<^esup>" |
|
1250 |
then have "\<forall>bs.\<lparr>p -\<^sub>p q\<rparr>\<^sub>p\<^bsup>bs\<^esup>= (0::'a)" |
|
1251 |
by simp |
|
1252 |
then have "\<forall>bs. wf_bs bs (p -\<^sub>p q) \<longrightarrow> \<lparr>p -\<^sub>p q\<rparr>\<^sub>p\<^bsup>bs\<^esup> = (0::'a)" |
|
33154 | 1253 |
using wf_bs_polysub[where p=p and q=q] by auto |
56000 | 1254 |
with isnpolyh_zero_iff[OF polysub_normh[OF np nq]] polysub_0[OF np nq] show "p = q" |
1255 |
by blast |
|
33154 | 1256 |
qed |
1257 |
||
1258 |
||
41404 | 1259 |
text{* consequences of unicity on the algorithms for polynomial normalization *} |
33154 | 1260 |
|
52658 | 1261 |
lemma polyadd_commute: |
56000 | 1262 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1263 |
and np: "isnpolyh p n0" |
1264 |
and nq: "isnpolyh q n1" |
|
1265 |
shows "p +\<^sub>p q = q +\<^sub>p p" |
|
56000 | 1266 |
using isnpolyh_unique[OF polyadd_normh[OF np nq] polyadd_normh[OF nq np]] |
1267 |
by simp |
|
33154 | 1268 |
|
56000 | 1269 |
lemma zero_normh: "isnpolyh 0\<^sub>p n" |
1270 |
by simp |
|
1271 |
||
1272 |
lemma one_normh: "isnpolyh (1)\<^sub>p n" |
|
1273 |
by simp |
|
52658 | 1274 |
|
52803 | 1275 |
lemma polyadd_0[simp]: |
56000 | 1276 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1277 |
and np: "isnpolyh p n0" |
56000 | 1278 |
shows "p +\<^sub>p 0\<^sub>p = p" |
1279 |
and "0\<^sub>p +\<^sub>p p = p" |
|
52803 | 1280 |
using isnpolyh_unique[OF polyadd_normh[OF np zero_normh] np] |
33154 | 1281 |
isnpolyh_unique[OF polyadd_normh[OF zero_normh np] np] by simp_all |
1282 |
||
52803 | 1283 |
lemma polymul_1[simp]: |
56000 | 1284 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1285 |
and np: "isnpolyh p n0" |
56000 | 1286 |
shows "p *\<^sub>p (1)\<^sub>p = p" |
1287 |
and "(1)\<^sub>p *\<^sub>p p = p" |
|
52803 | 1288 |
using isnpolyh_unique[OF polymul_normh[OF np one_normh] np] |
33154 | 1289 |
isnpolyh_unique[OF polymul_normh[OF one_normh np] np] by simp_all |
52658 | 1290 |
|
52803 | 1291 |
lemma polymul_0[simp]: |
56000 | 1292 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1293 |
and np: "isnpolyh p n0" |
56000 | 1294 |
shows "p *\<^sub>p 0\<^sub>p = 0\<^sub>p" |
1295 |
and "0\<^sub>p *\<^sub>p p = 0\<^sub>p" |
|
52803 | 1296 |
using isnpolyh_unique[OF polymul_normh[OF np zero_normh] zero_normh] |
33154 | 1297 |
isnpolyh_unique[OF polymul_normh[OF zero_normh np] zero_normh] by simp_all |
1298 |
||
52803 | 1299 |
lemma polymul_commute: |
56000 | 1300 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
1301 |
and np: "isnpolyh p n0" |
|
52658 | 1302 |
and nq: "isnpolyh q n1" |
33154 | 1303 |
shows "p *\<^sub>p q = q *\<^sub>p p" |
56043 | 1304 |
using isnpolyh_unique[OF polymul_normh[OF np nq] polymul_normh[OF nq np], |
1305 |
where ?'a = "'a::{field_char_0,field_inverse_zero, power}"] |
|
52658 | 1306 |
by simp |
33154 | 1307 |
|
52658 | 1308 |
declare polyneg_polyneg [simp] |
52803 | 1309 |
|
1310 |
lemma isnpolyh_polynate_id [simp]: |
|
56000 | 1311 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
1312 |
and np: "isnpolyh p n0" |
|
52658 | 1313 |
shows "polynate p = p" |
56043 | 1314 |
using isnpolyh_unique[where ?'a= "'a::{field_char_0,field_inverse_zero}", |
1315 |
OF polynate_norm[of p, unfolded isnpoly_def] np] |
|
1316 |
polynate[where ?'a = "'a::{field_char_0,field_inverse_zero}"] |
|
52658 | 1317 |
by simp |
33154 | 1318 |
|
52803 | 1319 |
lemma polynate_idempotent[simp]: |
56000 | 1320 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
33154 | 1321 |
shows "polynate (polynate p) = polynate p" |
1322 |
using isnpolyh_polynate_id[OF polynate_norm[of p, unfolded isnpoly_def]] . |
|
1323 |
||
1324 |
lemma poly_nate_polypoly': "poly_nate bs p = polypoly' bs (polynate p)" |
|
1325 |
unfolding poly_nate_def polypoly'_def .. |
|
52658 | 1326 |
|
1327 |
lemma poly_nate_poly: |
|
56000 | 1328 |
"poly (poly_nate bs p) = (\<lambda>x:: 'a ::{field_char_0,field_inverse_zero}. \<lparr>p\<rparr>\<^sub>p\<^bsup>x # bs\<^esup>)" |
33154 | 1329 |
using polypoly'_poly[OF polynate_norm[unfolded isnpoly_def], symmetric, of bs p] |
52658 | 1330 |
unfolding poly_nate_polypoly' by auto |
1331 |
||
33154 | 1332 |
|
1333 |
subsection{* heads, degrees and all that *} |
|
52658 | 1334 |
|
33154 | 1335 |
lemma degree_eq_degreen0: "degree p = degreen p 0" |
52658 | 1336 |
by (induct p rule: degree.induct) simp_all |
33154 | 1337 |
|
52658 | 1338 |
lemma degree_polyneg: |
56043 | 1339 |
assumes "isnpolyh p n" |
33154 | 1340 |
shows "degree (polyneg p) = degree p" |
56043 | 1341 |
apply (induct p rule: polyneg.induct) |
1342 |
using assms |
|
1343 |
apply simp_all |
|
52658 | 1344 |
apply (case_tac na) |
1345 |
apply auto |
|
1346 |
done |
|
33154 | 1347 |
|
1348 |
lemma degree_polyadd: |
|
56043 | 1349 |
assumes np: "isnpolyh p n0" |
1350 |
and nq: "isnpolyh q n1" |
|
33154 | 1351 |
shows "degree (p +\<^sub>p q) \<le> max (degree p) (degree q)" |
52658 | 1352 |
using degreen_polyadd[OF np nq, where m= "0"] degree_eq_degreen0 by simp |
33154 | 1353 |
|
1354 |
||
52658 | 1355 |
lemma degree_polysub: |
1356 |
assumes np: "isnpolyh p n0" |
|
1357 |
and nq: "isnpolyh q n1" |
|
33154 | 1358 |
shows "degree (p -\<^sub>p q) \<le> max (degree p) (degree q)" |
1359 |
proof- |
|
56043 | 1360 |
from nq have nq': "isnpolyh (~\<^sub>p q) n1" |
1361 |
using polyneg_normh by simp |
|
1362 |
from degree_polyadd[OF np nq'] show ?thesis |
|
1363 |
by (simp add: polysub_def degree_polyneg[OF nq]) |
|
33154 | 1364 |
qed |
1365 |
||
52803 | 1366 |
lemma degree_polysub_samehead: |
56000 | 1367 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56043 | 1368 |
and np: "isnpolyh p n0" |
1369 |
and nq: "isnpolyh q n1" |
|
1370 |
and h: "head p = head q" |
|
52658 | 1371 |
and d: "degree p = degree q" |
33154 | 1372 |
shows "degree (p -\<^sub>p q) < degree p \<or> (p -\<^sub>p q = 0\<^sub>p)" |
52658 | 1373 |
unfolding polysub_def split_def fst_conv snd_conv |
1374 |
using np nq h d |
|
1375 |
proof (induct p q rule: polyadd.induct) |
|
1376 |
case (1 c c') |
|
56009 | 1377 |
then show ?case |
1378 |
by (simp add: Nsub_def Nsub0[simplified Nsub_def]) |
|
33154 | 1379 |
next |
52803 | 1380 |
case (2 c c' n' p') |
56009 | 1381 |
from 2 have "degree (C c) = degree (CN c' n' p')" |
1382 |
by simp |
|
1383 |
then have nz: "n' > 0" |
|
1384 |
by (cases n') auto |
|
1385 |
then have "head (CN c' n' p') = CN c' n' p'" |
|
1386 |
by (cases n') auto |
|
1387 |
with 2 show ?case |
|
1388 |
by simp |
|
33154 | 1389 |
next |
52803 | 1390 |
case (3 c n p c') |
56009 | 1391 |
then have "degree (C c') = degree (CN c n p)" |
1392 |
by simp |
|
1393 |
then have nz: "n > 0" |
|
1394 |
by (cases n) auto |
|
1395 |
then have "head (CN c n p) = CN c n p" |
|
1396 |
by (cases n) auto |
|
41807 | 1397 |
with 3 show ?case by simp |
33154 | 1398 |
next |
1399 |
case (4 c n p c' n' p') |
|
56009 | 1400 |
then have H: |
1401 |
"isnpolyh (CN c n p) n0" |
|
1402 |
"isnpolyh (CN c' n' p') n1" |
|
1403 |
"head (CN c n p) = head (CN c' n' p')" |
|
1404 |
"degree (CN c n p) = degree (CN c' n' p')" |
|
1405 |
by simp_all |
|
1406 |
then have degc: "degree c = 0" and degc': "degree c' = 0" |
|
1407 |
by simp_all |
|
1408 |
then have degnc: "degree (~\<^sub>p c) = 0" and degnc': "degree (~\<^sub>p c') = 0" |
|
33154 | 1409 |
using H(1-2) degree_polyneg by auto |
56009 | 1410 |
from H have cnh: "isnpolyh c (Suc n)" and c'nh: "isnpolyh c' (Suc n')" |
1411 |
by simp_all |
|
1412 |
from degree_polysub[OF cnh c'nh, simplified polysub_def] degc degc' |
|
1413 |
have degcmc': "degree (c +\<^sub>p ~\<^sub>pc') = 0" |
|
1414 |
by simp |
|
1415 |
from H have pnh: "isnpolyh p n" and p'nh: "isnpolyh p' n'" |
|
1416 |
by auto |
|
1417 |
have "n = n' \<or> n < n' \<or> n > n'" |
|
1418 |
by arith |
|
33154 | 1419 |
moreover |
56009 | 1420 |
{ |
1421 |
assume nn': "n = n'" |
|
1422 |
have "n = 0 \<or> n > 0" by arith |
|
56066 | 1423 |
moreover |
1424 |
{ |
|
56009 | 1425 |
assume nz: "n = 0" |
1426 |
then have ?case using 4 nn' |
|
1427 |
by (auto simp add: Let_def degcmc') |
|
1428 |
} |
|
56066 | 1429 |
moreover |
1430 |
{ |
|
56009 | 1431 |
assume nz: "n > 0" |
1432 |
with nn' H(3) have cc': "c = c'" and pp': "p = p'" |
|
1433 |
by (cases n, auto)+ |
|
1434 |
then have ?case |
|
1435 |
using polysub_same_0[OF p'nh, simplified polysub_def split_def fst_conv snd_conv] |
|
1436 |
using polysub_same_0[OF c'nh, simplified polysub_def] |
|
1437 |
using nn' 4 by (simp add: Let_def) |
|
1438 |
} |
|
1439 |
ultimately have ?case by blast |
|
1440 |
} |
|
33154 | 1441 |
moreover |
56009 | 1442 |
{ |
1443 |
assume nn': "n < n'" |
|
1444 |
then have n'p: "n' > 0" |
|
1445 |
by simp |
|
1446 |
then have headcnp':"head (CN c' n' p') = CN c' n' p'" |
|
1447 |
by (cases n') simp_all |
|
1448 |
have degcnp': "degree (CN c' n' p') = 0" |
|
1449 |
and degcnpeq: "degree (CN c n p) = degree (CN c' n' p')" |
|
52658 | 1450 |
using 4 nn' by (cases n', simp_all) |
56009 | 1451 |
then have "n > 0" |
1452 |
by (cases n) simp_all |
|
1453 |
then have headcnp: "head (CN c n p) = CN c n p" |
|
1454 |
by (cases n) auto |
|
1455 |
from H(3) headcnp headcnp' nn' have ?case |
|
1456 |
by auto |
|
1457 |
} |
|
33154 | 1458 |
moreover |
56009 | 1459 |
{ |
1460 |
assume nn': "n > n'" |
|
1461 |
then have np: "n > 0" by simp |
|
1462 |
then have headcnp:"head (CN c n p) = CN c n p" |
|
1463 |
by (cases n) simp_all |
|
1464 |
from 4 have degcnpeq: "degree (CN c' n' p') = degree (CN c n p)" |
|
1465 |
by simp |
|
1466 |
from np have degcnp: "degree (CN c n p) = 0" |
|
1467 |
by (cases n) simp_all |
|
1468 |
with degcnpeq have "n' > 0" |
|
1469 |
by (cases n') simp_all |
|
1470 |
then have headcnp': "head (CN c' n' p') = CN c' n' p'" |
|
1471 |
by (cases n') auto |
|
1472 |
from H(3) headcnp headcnp' nn' have ?case by auto |
|
1473 |
} |
|
1474 |
ultimately show ?case by blast |
|
41812 | 1475 |
qed auto |
52803 | 1476 |
|
33154 | 1477 |
lemma shift1_head : "isnpolyh p n0 \<Longrightarrow> head (shift1 p) = head p" |
52658 | 1478 |
by (induct p arbitrary: n0 rule: head.induct) (simp_all add: shift1_def) |
33154 | 1479 |
|
1480 |
lemma funpow_shift1_head: "isnpolyh p n0 \<Longrightarrow> p\<noteq> 0\<^sub>p \<Longrightarrow> head (funpow k shift1 p) = head p" |
|
52658 | 1481 |
proof (induct k arbitrary: n0 p) |
1482 |
case 0 |
|
56198 | 1483 |
then show ?case |
1484 |
by auto |
|
52658 | 1485 |
next |
1486 |
case (Suc k n0 p) |
|
56066 | 1487 |
then have "isnpolyh (shift1 p) 0" |
1488 |
by (simp add: shift1_isnpolyh) |
|
41807 | 1489 |
with Suc have "head (funpow k shift1 (shift1 p)) = head (shift1 p)" |
56066 | 1490 |
and "head (shift1 p) = head p" |
1491 |
by (simp_all add: shift1_head) |
|
1492 |
then show ?case |
|
1493 |
by (simp add: funpow_swap1) |
|
52658 | 1494 |
qed |
33154 | 1495 |
|
1496 |
lemma shift1_degree: "degree (shift1 p) = 1 + degree p" |
|
1497 |
by (simp add: shift1_def) |
|
56009 | 1498 |
|
33154 | 1499 |
lemma funpow_shift1_degree: "degree (funpow k shift1 p) = k + degree p " |
46991 | 1500 |
by (induct k arbitrary: p) (auto simp add: shift1_degree) |
33154 | 1501 |
|
1502 |
lemma funpow_shift1_nz: "p \<noteq> 0\<^sub>p \<Longrightarrow> funpow n shift1 p \<noteq> 0\<^sub>p" |
|
52658 | 1503 |
by (induct n arbitrary: p) simp_all |
33154 | 1504 |
|
1505 |
lemma head_isnpolyh_Suc[simp]: "isnpolyh p (Suc n) \<Longrightarrow> head p = p" |
|
52658 | 1506 |
by (induct p arbitrary: n rule: degree.induct) auto |
33154 | 1507 |
lemma headn_0[simp]: "isnpolyh p n \<Longrightarrow> m < n \<Longrightarrow> headn p m = p" |
52658 | 1508 |
by (induct p arbitrary: n rule: degreen.induct) auto |
33154 | 1509 |
lemma head_isnpolyh_Suc': "n > 0 \<Longrightarrow> isnpolyh p n \<Longrightarrow> head p = p" |
52658 | 1510 |
by (induct p arbitrary: n rule: degree.induct) auto |
33154 | 1511 |
lemma head_head[simp]: "isnpolyh p n0 \<Longrightarrow> head (head p) = head p" |
52658 | 1512 |
by (induct p rule: head.induct) auto |
33154 | 1513 |
|
52803 | 1514 |
lemma polyadd_eq_const_degree: |
52658 | 1515 |
"isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> polyadd p q = C c \<Longrightarrow> degree p = degree q" |
33154 | 1516 |
using polyadd_eq_const_degreen degree_eq_degreen0 by simp |
1517 |
||
52658 | 1518 |
lemma polyadd_head: |
1519 |
assumes np: "isnpolyh p n0" |
|
1520 |
and nq: "isnpolyh q n1" |
|
1521 |
and deg: "degree p \<noteq> degree q" |
|
33154 | 1522 |
shows "head (p +\<^sub>p q) = (if degree p < degree q then head q else head p)" |
52658 | 1523 |
using np nq deg |
1524 |
apply (induct p q arbitrary: n0 n1 rule: polyadd.induct) |
|
1525 |
apply simp_all |
|
1526 |
apply (case_tac n', simp, simp) |
|
1527 |
apply (case_tac n, simp, simp) |
|
1528 |
apply (case_tac n, case_tac n', simp add: Let_def) |
|
54489
03ff4d1e6784
eliminiated neg_numeral in favour of - (numeral _)
haftmann
parents:
54220
diff
changeset
|
1529 |
apply (auto simp add: polyadd_eq_const_degree)[2] |
52658 | 1530 |
apply (metis head_nz) |
1531 |
apply (metis head_nz) |
|
1532 |
apply (metis degree.simps(9) gr0_conv_Suc head.simps(1) less_Suc0 not_less_eq) |
|
1533 |
done |
|
33154 | 1534 |
|
52803 | 1535 |
lemma polymul_head_polyeq: |
56000 | 1536 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56066 | 1537 |
shows "isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> p \<noteq> 0\<^sub>p \<Longrightarrow> q \<noteq> 0\<^sub>p \<Longrightarrow> head (p *\<^sub>p q) = head p *\<^sub>p head q" |
33154 | 1538 |
proof (induct p q arbitrary: n0 n1 rule: polymul.induct) |
41813 | 1539 |
case (2 c c' n' p' n0 n1) |
56009 | 1540 |
then have "isnpolyh (head (CN c' n' p')) n1" "isnormNum c" |
1541 |
by (simp_all add: head_isnpolyh) |
|
1542 |
then show ?case |
|
1543 |
using 2 by (cases n') auto |
|
52803 | 1544 |
next |
1545 |
case (3 c n p c' n0 n1) |
|
56009 | 1546 |
then have "isnpolyh (head (CN c n p)) n0" "isnormNum c'" |
1547 |
by (simp_all add: head_isnpolyh) |
|
56066 | 1548 |
then show ?case |
1549 |
using 3 by (cases n) auto |
|
33154 | 1550 |
next |
1551 |
case (4 c n p c' n' p' n0 n1) |
|
56066 | 1552 |
then have norm: "isnpolyh p n" "isnpolyh c (Suc n)" "isnpolyh p' n'" "isnpolyh c' (Suc n')" |
33154 | 1553 |
"isnpolyh (CN c n p) n" "isnpolyh (CN c' n' p') n'" |
1554 |
by simp_all |
|
1555 |
have "n < n' \<or> n' < n \<or> n = n'" by arith |
|
52803 | 1556 |
moreover |
56009 | 1557 |
{ |
1558 |
assume nn': "n < n'" |
|
1559 |
then have ?case |
|
52658 | 1560 |
using norm "4.hyps"(2)[OF norm(1,6)] "4.hyps"(1)[OF norm(2,6)] |
1561 |
apply simp |
|
1562 |
apply (cases n) |
|
1563 |
apply simp |
|
1564 |
apply (cases n') |
|
1565 |
apply simp_all |
|
56009 | 1566 |
done |
1567 |
} |
|
1568 |
moreover { |
|
1569 |
assume nn': "n'< n" |
|
1570 |
then have ?case |
|
52803 | 1571 |
using norm "4.hyps"(6) [OF norm(5,3)] "4.hyps"(5)[OF norm(5,4)] |
52658 | 1572 |
apply simp |
1573 |
apply (cases n') |
|
1574 |
apply simp |
|
1575 |
apply (cases n) |
|
1576 |
apply auto |
|
56009 | 1577 |
done |
1578 |
} |
|
56066 | 1579 |
moreover |
1580 |
{ |
|
56009 | 1581 |
assume nn': "n' = n" |
52803 | 1582 |
from nn' polymul_normh[OF norm(5,4)] |
33154 | 1583 |
have ncnpc':"isnpolyh (CN c n p *\<^sub>p c') n" by (simp add: min_def) |
52803 | 1584 |
from nn' polymul_normh[OF norm(5,3)] norm |
33154 | 1585 |
have ncnpp':"isnpolyh (CN c n p *\<^sub>p p') n" by simp |
1586 |
from nn' ncnpp' polymul_eq0_iff[OF norm(5,3)] norm(6) |
|
52803 | 1587 |
have ncnpp0':"isnpolyh (CN 0\<^sub>p n (CN c n p *\<^sub>p p')) n" by simp |
1588 |
from polyadd_normh[OF ncnpc' ncnpp0'] |
|
1589 |
have nth: "isnpolyh ((CN c n p *\<^sub>p c') +\<^sub>p (CN 0\<^sub>p n (CN c n p *\<^sub>p p'))) n" |
|
33154 | 1590 |
by (simp add: min_def) |
56009 | 1591 |
{ |
1592 |
assume np: "n > 0" |
|
33154 | 1593 |
with nn' head_isnpolyh_Suc'[OF np nth] |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1594 |
head_isnpolyh_Suc'[OF np norm(5)] head_isnpolyh_Suc'[OF np norm(6)[simplified nn']] |
56009 | 1595 |
have ?case by simp |
1596 |
} |
|
33154 | 1597 |
moreover |
56009 | 1598 |
{ |
1599 |
assume nz: "n = 0" |
|
33154 | 1600 |
from polymul_degreen[OF norm(5,4), where m="0"] |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1601 |
polymul_degreen[OF norm(5,3), where m="0"] nn' nz degree_eq_degreen0 |
33154 | 1602 |
norm(5,6) degree_npolyhCN[OF norm(6)] |
56066 | 1603 |
have dth: "degree (CN c 0 p *\<^sub>p c') < degree (CN 0\<^sub>p 0 (CN c 0 p *\<^sub>p p'))" |
1604 |
by simp |
|
1605 |
then have dth': "degree (CN c 0 p *\<^sub>p c') \<noteq> degree (CN 0\<^sub>p 0 (CN c 0 p *\<^sub>p p'))" |
|
1606 |
by simp |
|
33154 | 1607 |
from polyadd_head[OF ncnpc'[simplified nz] ncnpp0'[simplified nz] dth'] dth |
56066 | 1608 |
have ?case |
1609 |
using norm "4.hyps"(6)[OF norm(5,3)] "4.hyps"(5)[OF norm(5,4)] nn' nz |
|
1610 |
by simp |
|
56009 | 1611 |
} |
56066 | 1612 |
ultimately have ?case |
1613 |
by (cases n) auto |
|
56009 | 1614 |
} |
33154 | 1615 |
ultimately show ?case by blast |
1616 |
qed simp_all |
|
1617 |
||
1618 |
lemma degree_coefficients: "degree p = length (coefficients p) - 1" |
|
52658 | 1619 |
by (induct p rule: degree.induct) auto |
33154 | 1620 |
|
1621 |
lemma degree_head[simp]: "degree (head p) = 0" |
|
52658 | 1622 |
by (induct p rule: head.induct) auto |
33154 | 1623 |
|
41812 | 1624 |
lemma degree_CN: "isnpolyh p n \<Longrightarrow> degree (CN c n p) \<le> 1 + degree p" |
52658 | 1625 |
by (cases n) simp_all |
56066 | 1626 |
|
33154 | 1627 |
lemma degree_CN': "isnpolyh p n \<Longrightarrow> degree (CN c n p) \<ge> degree p" |
52658 | 1628 |
by (cases n) simp_all |
33154 | 1629 |
|
52658 | 1630 |
lemma polyadd_different_degree: |
56066 | 1631 |
"isnpolyh p n0 \<Longrightarrow> isnpolyh q n1 \<Longrightarrow> degree p \<noteq> degree q \<Longrightarrow> |
52658 | 1632 |
degree (polyadd p q) = max (degree p) (degree q)" |
33154 | 1633 |
using polyadd_different_degreen degree_eq_degreen0 by simp |
1634 |
||
1635 |
lemma degreen_polyneg: "isnpolyh p n0 \<Longrightarrow> degreen (~\<^sub>p p) m = degreen p m" |
|
52658 | 1636 |
by (induct p arbitrary: n0 rule: polyneg.induct) auto |
33154 | 1637 |
|
1638 |
lemma degree_polymul: |
|
56000 | 1639 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1640 |
and np: "isnpolyh p n0" |
1641 |
and nq: "isnpolyh q n1" |
|
33154 | 1642 |
shows "degree (p *\<^sub>p q) \<le> degree p + degree q" |
1643 |
using polymul_degreen[OF np nq, where m="0"] degree_eq_degreen0 by simp |
|
1644 |
||
1645 |
lemma polyneg_degree: "isnpolyh p n \<Longrightarrow> degree (polyneg p) = degree p" |
|
52658 | 1646 |
by (induct p arbitrary: n rule: degree.induct) auto |
33154 | 1647 |
|
56207 | 1648 |
lemma polyneg_head: "isnpolyh p n \<Longrightarrow> head (polyneg p) = polyneg (head p)" |
52658 | 1649 |
by (induct p arbitrary: n rule: degree.induct) auto |
1650 |
||
33154 | 1651 |
|
1652 |
subsection {* Correctness of polynomial pseudo division *} |
|
1653 |
||
1654 |
lemma polydivide_aux_properties: |
|
56000 | 1655 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
52658 | 1656 |
and np: "isnpolyh p n0" |
1657 |
and ns: "isnpolyh s n1" |
|
1658 |
and ap: "head p = a" |
|
56198 | 1659 |
and ndp: "degree p = n" |
1660 |
and pnz: "p \<noteq> 0\<^sub>p" |
|
1661 |
shows "polydivide_aux a n p k s = (k', r) \<longrightarrow> k' \<ge> k \<and> (degree r = 0 \<or> degree r < degree p) \<and> |
|
56066 | 1662 |
(\<exists>nr. isnpolyh r nr) \<and> (\<exists>q n1. isnpolyh q n1 \<and> (polypow (k' - k) a) *\<^sub>p s = p *\<^sub>p q +\<^sub>p r)" |
33154 | 1663 |
using ns |
52658 | 1664 |
proof (induct "degree s" arbitrary: s k k' r n1 rule: less_induct) |
34915 | 1665 |
case less |
33154 | 1666 |
let ?qths = "\<exists>q n1. isnpolyh q n1 \<and> (a ^\<^sub>p (k' - k) *\<^sub>p s = p *\<^sub>p q +\<^sub>p r)" |
56066 | 1667 |
let ?ths = "polydivide_aux a n p k s = (k', r) \<longrightarrow> k \<le> k' \<and> |
1668 |
(degree r = 0 \<or> degree r < degree p) \<and> (\<exists>nr. isnpolyh r nr) \<and> ?qths" |
|
33154 | 1669 |
let ?b = "head s" |
34915 | 1670 |
let ?p' = "funpow (degree s - n) shift1 p" |
50282
fe4d4bb9f4c2
more robust syntax that survives collapse of \<^isub> and \<^sub>;
wenzelm
parents:
49962
diff
changeset
|
1671 |
let ?xdn = "funpow (degree s - n) shift1 (1)\<^sub>p" |
33154 | 1672 |
let ?akk' = "a ^\<^sub>p (k' - k)" |
34915 | 1673 |
note ns = `isnpolyh s n1` |
52803 | 1674 |
from np have np0: "isnpolyh p 0" |
1675 |
using isnpolyh_mono[where n="n0" and n'="0" and p="p"] by simp |
|
1676 |
have np': "isnpolyh ?p' 0" |
|
1677 |
using funpow_shift1_isnpoly[OF np0[simplified isnpoly_def[symmetric]] pnz, where n="degree s - n"] isnpoly_def |
|
1678 |
by simp |
|
1679 |
have headp': "head ?p' = head p" |
|
1680 |
using funpow_shift1_head[OF np pnz] by simp |
|
1681 |
from funpow_shift1_isnpoly[where p="(1)\<^sub>p"] have nxdn: "isnpolyh ?xdn 0" |
|
1682 |
by (simp add: isnpoly_def) |
|
1683 |
from polypow_normh [OF head_isnpolyh[OF np0], where k="k' - k"] ap |
|
33154 | 1684 |
have nakk':"isnpolyh ?akk' 0" by blast |
56066 | 1685 |
{ |
1686 |
assume sz: "s = 0\<^sub>p" |
|
1687 |
then have ?ths |
|
1688 |
using np polydivide_aux.simps |
|
52658 | 1689 |
apply clarsimp |
1690 |
apply (rule exI[where x="0\<^sub>p"]) |
|
1691 |
apply simp |
|
56066 | 1692 |
done |
1693 |
} |
|
33154 | 1694 |
moreover |
56066 | 1695 |
{ |
1696 |
assume sz: "s \<noteq> 0\<^sub>p" |
|
1697 |
{ |
|
1698 |
assume dn: "degree s < n" |
|
1699 |
then have "?ths" |
|
1700 |
using ns ndp np polydivide_aux.simps |
|
52658 | 1701 |
apply auto |
1702 |
apply (rule exI[where x="0\<^sub>p"]) |
|
1703 |
apply simp |
|
56066 | 1704 |
done |
1705 |
} |
|
52803 | 1706 |
moreover |
56066 | 1707 |
{ |
1708 |
assume dn': "\<not> degree s < n" |
|
1709 |
then have dn: "degree s \<ge> n" |
|
1710 |
by arith |
|
52803 | 1711 |
have degsp': "degree s = degree ?p'" |
56066 | 1712 |
using dn ndp funpow_shift1_degree[where k = "degree s - n" and p="p"] |
1713 |
by simp |
|
1714 |
{ |
|
1715 |
assume ba: "?b = a" |
|
1716 |
then have headsp': "head s = head ?p'" |
|
52803 | 1717 |
using ap headp' by simp |
1718 |
have nr: "isnpolyh (s -\<^sub>p ?p') 0" |
|
1719 |
using polysub_normh[OF ns np'] by simp |
|
34915 | 1720 |
from degree_polysub_samehead[OF ns np' headsp' degsp'] |
56207 | 1721 |
have "degree (s -\<^sub>p ?p') < degree s \<or> s -\<^sub>p ?p' = 0\<^sub>p" |
1722 |
by simp |
|
52803 | 1723 |
moreover |
56066 | 1724 |
{ |
1725 |
assume deglt:"degree (s -\<^sub>p ?p') < degree s" |
|
41403
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1726 |
from polydivide_aux.simps sz dn' ba |
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1727 |
have eq: "polydivide_aux a n p k s = polydivide_aux a n p k (s -\<^sub>p ?p')" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1728 |
by (simp add: Let_def) |
56066 | 1729 |
{ |
1730 |
assume h1: "polydivide_aux a n p k s = (k', r)" |
|
52803 | 1731 |
from less(1)[OF deglt nr, of k k' r] trans[OF eq[symmetric] h1] |
1732 |
have kk': "k \<le> k'" |
|
56066 | 1733 |
and nr: "\<exists>nr. isnpolyh r nr" |
52803 | 1734 |
and dr: "degree r = 0 \<or> degree r < degree p" |
56066 | 1735 |
and q1: "\<exists>q nq. isnpolyh q nq \<and> a ^\<^sub>p k' - k *\<^sub>p (s -\<^sub>p ?p') = p *\<^sub>p q +\<^sub>p r" |
52803 | 1736 |
by auto |
1737 |
from q1 obtain q n1 where nq: "isnpolyh q n1" |
|
56066 | 1738 |
and asp: "a^\<^sub>p (k' - k) *\<^sub>p (s -\<^sub>p ?p') = p *\<^sub>p q +\<^sub>p r" |
1739 |
by blast |
|
1740 |
from nr obtain nr where nr': "isnpolyh r nr" |
|
1741 |
by blast |
|
52803 | 1742 |
from polymul_normh[OF nakk' ns] have nakks': "isnpolyh (a ^\<^sub>p (k' - k) *\<^sub>p s) 0" |
1743 |
by simp |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1744 |
from polyadd_normh[OF polymul_normh[OF nakk' nxdn] nq] |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1745 |
have nq': "isnpolyh (?akk' *\<^sub>p ?xdn +\<^sub>p q) 0" by simp |
52803 | 1746 |
from polyadd_normh[OF polymul_normh[OF np |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1747 |
polyadd_normh[OF polymul_normh[OF nakk' nxdn] nq]] nr'] |
52803 | 1748 |
have nqr': "isnpolyh (p *\<^sub>p (?akk' *\<^sub>p ?xdn +\<^sub>p q) +\<^sub>p r) 0" |
1749 |
by simp |
|
56066 | 1750 |
from asp have "\<forall>bs :: 'a::{field_char_0,field_inverse_zero} list. |
1751 |
Ipoly bs (a^\<^sub>p (k' - k) *\<^sub>p (s -\<^sub>p ?p')) = Ipoly bs (p *\<^sub>p q +\<^sub>p r)" |
|
1752 |
by simp |
|
1753 |
then have "\<forall>bs :: 'a::{field_char_0,field_inverse_zero} list. |
|
1754 |
Ipoly bs (a^\<^sub>p (k' - k)*\<^sub>p s) = |
|
52803 | 1755 |
Ipoly bs (a^\<^sub>p (k' - k)) * Ipoly bs ?p' + Ipoly bs p * Ipoly bs q + Ipoly bs r" |
36349 | 1756 |
by (simp add: field_simps) |
56066 | 1757 |
then have "\<forall>bs :: 'a::{field_char_0,field_inverse_zero} list. |
1758 |
Ipoly bs (a ^\<^sub>p (k' - k) *\<^sub>p s) = |
|
52803 | 1759 |
Ipoly bs (a^\<^sub>p (k' - k)) * Ipoly bs (funpow (degree s - n) shift1 (1)\<^sub>p *\<^sub>p p) + |
1760 |
Ipoly bs p * Ipoly bs q + Ipoly bs r" |
|
1761 |
by (auto simp only: funpow_shift1_1) |
|
56066 | 1762 |
then have "\<forall>bs:: 'a::{field_char_0,field_inverse_zero} list. |
1763 |
Ipoly bs (a ^\<^sub>p (k' - k) *\<^sub>p s) = |
|
52803 | 1764 |
Ipoly bs p * (Ipoly bs (a^\<^sub>p (k' - k)) * Ipoly bs (funpow (degree s - n) shift1 (1)\<^sub>p) + |
1765 |
Ipoly bs q) + Ipoly bs r" |
|
1766 |
by (simp add: field_simps) |
|
56066 | 1767 |
then have "\<forall>bs:: 'a::{field_char_0,field_inverse_zero} list. |
1768 |
Ipoly bs (a ^\<^sub>p (k' - k) *\<^sub>p s) = |
|
52803 | 1769 |
Ipoly bs (p *\<^sub>p ((a^\<^sub>p (k' - k)) *\<^sub>p (funpow (degree s - n) shift1 (1)\<^sub>p) +\<^sub>p q) +\<^sub>p r)" |
1770 |
by simp |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1771 |
with isnpolyh_unique[OF nakks' nqr'] |
52803 | 1772 |
have "a ^\<^sub>p (k' - k) *\<^sub>p s = |
1773 |
p *\<^sub>p ((a^\<^sub>p (k' - k)) *\<^sub>p (funpow (degree s - n) shift1 (1)\<^sub>p) +\<^sub>p q) +\<^sub>p r" |
|
1774 |
by blast |
|
56066 | 1775 |
then have ?qths using nq' |
50282
fe4d4bb9f4c2
more robust syntax that survives collapse of \<^isub> and \<^sub>;
wenzelm
parents:
49962
diff
changeset
|
1776 |
apply (rule_tac x="(a^\<^sub>p (k' - k)) *\<^sub>p (funpow (degree s - n) shift1 (1)\<^sub>p) +\<^sub>p q" in exI) |
52803 | 1777 |
apply (rule_tac x="0" in exI) |
1778 |
apply simp |
|
1779 |
done |
|
56066 | 1780 |
with kk' nr dr have "k \<le> k' \<and> (degree r = 0 \<or> degree r < degree p) \<and> |
1781 |
(\<exists>nr. isnpolyh r nr) \<and> ?qths" |
|
52803 | 1782 |
by blast |
1783 |
} |
|
56066 | 1784 |
then have ?ths by blast |
52803 | 1785 |
} |
1786 |
moreover |
|
56066 | 1787 |
{ |
1788 |
assume spz:"s -\<^sub>p ?p' = 0\<^sub>p" |
|
56000 | 1789 |
from spz isnpolyh_unique[OF polysub_normh[OF ns np'], where q="0\<^sub>p", symmetric, where ?'a = "'a::{field_char_0,field_inverse_zero}"] |
56066 | 1790 |
have "\<forall>bs:: 'a::{field_char_0,field_inverse_zero} list. Ipoly bs s = Ipoly bs ?p'" |
52803 | 1791 |
by simp |
56066 | 1792 |
then have "\<forall>bs:: 'a::{field_char_0,field_inverse_zero} list. Ipoly bs s = Ipoly bs (?xdn *\<^sub>p p)" |
52658 | 1793 |
using np nxdn |
1794 |
apply simp |
|
1795 |
apply (simp only: funpow_shift1_1) |
|
1796 |
apply simp |
|
1797 |
done |
|
56066 | 1798 |
then have sp': "s = ?xdn *\<^sub>p p" |
1799 |
using isnpolyh_unique[OF ns polymul_normh[OF nxdn np]] |
|
52658 | 1800 |
by blast |
56066 | 1801 |
{ |
56207 | 1802 |
assume h1: "polydivide_aux a n p k s = (k', r)" |
41403
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1803 |
from polydivide_aux.simps sz dn' ba |
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1804 |
have eq: "polydivide_aux a n p k s = polydivide_aux a n p k (s -\<^sub>p ?p')" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1805 |
by (simp add: Let_def) |
52803 | 1806 |
also have "\<dots> = (k,0\<^sub>p)" |
1807 |
using polydivide_aux.simps spz by simp |
|
56066 | 1808 |
finally have "(k', r) = (k, 0\<^sub>p)" |
1809 |
using h1 by simp |
|
34915 | 1810 |
with sp'[symmetric] ns np nxdn polyadd_0(1)[OF polymul_normh[OF np nxdn]] |
41403
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1811 |
polyadd_0(2)[OF polymul_normh[OF np nxdn]] have ?ths |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1812 |
apply auto |
52803 | 1813 |
apply (rule exI[where x="?xdn"]) |
34915 | 1814 |
apply (auto simp add: polymul_commute[of p]) |
52803 | 1815 |
done |
1816 |
} |
|
1817 |
} |
|
1818 |
ultimately have ?ths by blast |
|
1819 |
} |
|
33154 | 1820 |
moreover |
56066 | 1821 |
{ |
1822 |
assume ba: "?b \<noteq> a" |
|
52803 | 1823 |
from polysub_normh[OF polymul_normh[OF head_isnpolyh[OF np0, simplified ap] ns] |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1824 |
polymul_normh[OF head_isnpolyh[OF ns] np']] |
52803 | 1825 |
have nth: "isnpolyh ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p')) 0" |
1826 |
by (simp add: min_def) |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1827 |
have nzths: "a *\<^sub>p s \<noteq> 0\<^sub>p" "?b *\<^sub>p ?p' \<noteq> 0\<^sub>p" |
52803 | 1828 |
using polymul_eq0_iff[OF head_isnpolyh[OF np0, simplified ap] ns] |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1829 |
polymul_eq0_iff[OF head_isnpolyh[OF ns] np']head_nz[OF np0] ap pnz sz head_nz[OF ns] |
52803 | 1830 |
funpow_shift1_nz[OF pnz] |
1831 |
by simp_all |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1832 |
from polymul_head_polyeq[OF head_isnpolyh[OF np] ns] head_nz[OF np] sz ap head_head[OF np] pnz |
34915 | 1833 |
polymul_head_polyeq[OF head_isnpolyh[OF ns] np'] head_nz [OF ns] sz funpow_shift1_nz[OF pnz, where n="degree s - n"] |
52803 | 1834 |
have hdth: "head (a *\<^sub>p s) = head (?b *\<^sub>p ?p')" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1835 |
using head_head[OF ns] funpow_shift1_head[OF np pnz] |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1836 |
polymul_commute[OF head_isnpolyh[OF np] head_isnpolyh[OF ns]] |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1837 |
by (simp add: ap) |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1838 |
from polymul_degreen[OF head_isnpolyh[OF np] ns, where m="0"] |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1839 |
head_nz[OF np] pnz sz ap[symmetric] |
34915 | 1840 |
funpow_shift1_nz[OF pnz, where n="degree s - n"] |
52803 | 1841 |
polymul_degreen[OF head_isnpolyh[OF ns] np', where m="0"] head_nz[OF ns] |
34915 | 1842 |
ndp dn |
52803 | 1843 |
have degth: "degree (a *\<^sub>p s) = degree (?b *\<^sub>p ?p')" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1844 |
by (simp add: degree_eq_degreen0[symmetric] funpow_shift1_degree) |
56066 | 1845 |
{ |
1846 |
assume dth: "degree ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p')) < degree s" |
|
52803 | 1847 |
from polysub_normh[OF polymul_normh[OF head_isnpolyh[OF np] ns] |
1848 |
polymul_normh[OF head_isnpolyh[OF ns]np']] ap |
|
1849 |
have nasbp': "isnpolyh ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p')) 0" |
|
1850 |
by simp |
|
56066 | 1851 |
{ |
1852 |
assume h1:"polydivide_aux a n p k s = (k', r)" |
|
41403
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1853 |
from h1 polydivide_aux.simps sz dn' ba |
7eba049f7310
partial_function (tailrec) replaces function (tailrec);
krauss
parents:
39246
diff
changeset
|
1854 |
have eq:"polydivide_aux a n p (Suc k) ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p')) = (k',r)" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1855 |
by (simp add: Let_def) |
34915 | 1856 |
with less(1)[OF dth nasbp', of "Suc k" k' r] |
52803 | 1857 |
obtain q nq nr where kk': "Suc k \<le> k'" |
1858 |
and nr: "isnpolyh r nr" |
|
1859 |
and nq: "isnpolyh q nq" |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1860 |
and dr: "degree r = 0 \<or> degree r < degree p" |
52803 | 1861 |
and qr: "a ^\<^sub>p (k' - Suc k) *\<^sub>p ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p')) = p *\<^sub>p q +\<^sub>p r" |
1862 |
by auto |
|
56066 | 1863 |
from kk' have kk'': "Suc (k' - Suc k) = k' - k" |
1864 |
by arith |
|
52803 | 1865 |
{ |
56066 | 1866 |
fix bs :: "'a::{field_char_0,field_inverse_zero} list" |
52803 | 1867 |
from qr isnpolyh_unique[OF polypow_normh[OF head_isnpolyh[OF np], where k="k' - Suc k", simplified ap] nasbp', symmetric] |
1868 |
have "Ipoly bs (a ^\<^sub>p (k' - Suc k) *\<^sub>p ((a *\<^sub>p s) -\<^sub>p (?b *\<^sub>p ?p'))) = Ipoly bs (p *\<^sub>p q +\<^sub>p r)" |
|
1869 |
by simp |
|
56066 | 1870 |
then have "Ipoly bs a ^ (Suc (k' - Suc k)) * Ipoly bs s = |
52803 | 1871 |
Ipoly bs p * Ipoly bs q + Ipoly bs a ^ (k' - Suc k) * Ipoly bs ?b * Ipoly bs ?p' + Ipoly bs r" |
1872 |
by (simp add: field_simps) |
|
56066 | 1873 |
then have "Ipoly bs a ^ (k' - k) * Ipoly bs s = |
52803 | 1874 |
Ipoly bs p * Ipoly bs q + Ipoly bs a ^ (k' - Suc k) * Ipoly bs ?b * Ipoly bs ?xdn * Ipoly bs p + Ipoly bs r" |
1875 |
by (simp add: kk'' funpow_shift1_1[where n="degree s - n" and p="p"]) |
|
56066 | 1876 |
then have "Ipoly bs (a ^\<^sub>p (k' - k) *\<^sub>p s) = |
52803 | 1877 |
Ipoly bs p * (Ipoly bs q + Ipoly bs a ^ (k' - Suc k) * Ipoly bs ?b * Ipoly bs ?xdn) + Ipoly bs r" |
1878 |
by (simp add: field_simps) |
|
1879 |
} |
|
56066 | 1880 |
then have ieq:"\<forall>bs :: 'a::{field_char_0,field_inverse_zero} list. |
56207 | 1881 |
Ipoly bs (a ^\<^sub>p (k' - k) *\<^sub>p s) = |
1882 |
Ipoly bs (p *\<^sub>p (q +\<^sub>p (a ^\<^sub>p (k' - Suc k) *\<^sub>p ?b *\<^sub>p ?xdn)) +\<^sub>p r)" |
|
52803 | 1883 |
by auto |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1884 |
let ?q = "q +\<^sub>p (a ^\<^sub>p (k' - Suc k) *\<^sub>p ?b *\<^sub>p ?xdn)" |
56207 | 1885 |
from polyadd_normh[OF nq polymul_normh[OF polymul_normh[OF polypow_normh[OF head_isnpolyh[OF np], where k="k' - Suc k"] head_isnpolyh[OF ns], simplified ap] nxdn]] |
52803 | 1886 |
have nqw: "isnpolyh ?q 0" |
1887 |
by simp |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1888 |
from ieq isnpolyh_unique[OF polymul_normh[OF polypow_normh[OF head_isnpolyh[OF np], where k="k' - k"] ns, simplified ap] polyadd_normh[OF polymul_normh[OF np nqw] nr]] |
52803 | 1889 |
have asth: "(a ^\<^sub>p (k' - k) *\<^sub>p s) = p *\<^sub>p (q +\<^sub>p (a ^\<^sub>p (k' - Suc k) *\<^sub>p ?b *\<^sub>p ?xdn)) +\<^sub>p r" |
1890 |
by blast |
|
1891 |
from dr kk' nr h1 asth nqw have ?ths |
|
1892 |
apply simp |
|
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1893 |
apply (rule conjI) |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1894 |
apply (rule exI[where x="nr"], simp) |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1895 |
apply (rule exI[where x="(q +\<^sub>p (a ^\<^sub>p (k' - Suc k) *\<^sub>p ?b *\<^sub>p ?xdn))"], simp) |
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1896 |
apply (rule exI[where x="0"], simp) |
52803 | 1897 |
done |
1898 |
} |
|
56066 | 1899 |
then have ?ths by blast |
52803 | 1900 |
} |
1901 |
moreover |
|
56066 | 1902 |
{ |
1903 |
assume spz: "a *\<^sub>p s -\<^sub>p (?b *\<^sub>p ?p') = 0\<^sub>p" |
|
52803 | 1904 |
{ |
56000 | 1905 |
fix bs :: "'a::{field_char_0,field_inverse_zero} list" |
33268
02de0317f66f
eliminated hard tabulators, guessing at each author's individual tab-width;
wenzelm
parents:
33154
diff
changeset
|
1906 |
from isnpolyh_unique[OF nth, where ?'a="'a" and q="0\<^sub>p",simplified,symmetric] spz |
52803 | 1907 |
have "Ipoly bs (a*\<^sub>p s) = Ipoly bs ?b * Ipoly bs ?p'" |
1908 |
by simp |
|
56066 | 1909 |
then have "Ipoly bs (a*\<^sub>p s) = Ipoly bs (?b *\<^sub>p ?xdn) * Ipoly bs p" |
52803 | 1910 |
by (simp add: funpow_shift1_1[where n="degree s - n" and p="p"]) |
56066 | 1911 |
then have "Ipoly bs (a*\<^sub>p s) = Ipoly bs (p *\<^sub>p (?b *\<^sub>p ?xdn))" |
52803 | 1912 |
by simp |
1913 |
} |
|
56066 | 1914 |
then have hth: "\<forall>bs :: 'a::{field_char_0,field_inverse_zero} list. |
1915 |
Ipoly bs (a *\<^sub>p s) = Ipoly bs (p *\<^sub>p (?b *\<^sub>p ?xdn))" .. |
|
52803 | 1916 |
from hth have asq: "a *\<^sub>p s = p *\<^sub>p (?b *\<^sub>p ?xdn)" |
56000 | 1917 |
using isnpolyh_unique[where ?'a = "'a::{field_char_0,field_inverse_zero}", OF polymul_normh[OF head_isnpolyh[OF np] ns] |
33154 | 1918 |
polymul_normh[OF np polymul_normh[OF head_isnpolyh[OF ns] nxdn]], |
56066 | 1919 |
simplified ap] |
1920 |
by simp |
|
1921 |
{ |
|
1922 |
assume h1: "polydivide_aux a n p k s = (k', r)" |
|
52803 | 1923 |
from h1 sz ba dn' spz polydivide_aux.simps polydivide_aux.simps |
56066 | 1924 |
have "(k', r) = (Suc k, 0\<^sub>p)" |
1925 |
by (simp add: Let_def) |
|
52803 | 1926 |
with h1 np head_isnpolyh[OF np, simplified ap] ns polymul_normh[OF head_isnpolyh[OF ns] nxdn] |
1927 |
polymul_normh[OF np polymul_normh[OF head_isnpolyh[OF ns] nxdn]] asq |
|
1928 |
have ?ths |
|
1929 |
apply (clarsimp simp add: Let_def) |
|
1930 |
apply (rule exI[where x="?b *\<^sub>p ?xdn"]) |
|
1931 |
apply simp |
|
1932 |
apply (rule exI[where x="0"], simp) |
|
1933 |
done |
|
1934 |
} |
|
56066 | 1935 |
then have ?ths by blast |
52803 | 1936 |
} |
52658 | 1937 |
ultimately have ?ths |
56066 | 1938 |
using degree_polysub_samehead[OF polymul_normh[OF head_isnpolyh[OF np0, simplified ap] ns] polymul_normh[OF head_isnpolyh[OF ns] np'] hdth degth] polymul_degreen[OF head_isnpolyh[OF np] ns, where m="0"] |
52658 | 1939 |
head_nz[OF np] pnz sz ap[symmetric] |
56066 | 1940 |
by (auto simp add: degree_eq_degreen0[symmetric]) |
52803 | 1941 |
} |
33154 | 1942 |
ultimately have ?ths by blast |
1943 |
} |
|
52803 | 1944 |
ultimately have ?ths by blast |
1945 |
} |
|
33154 | 1946 |
ultimately show ?ths by blast |
1947 |
qed |
|
1948 |
||
52803 | 1949 |
lemma polydivide_properties: |
56000 | 1950 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
56066 | 1951 |
and np: "isnpolyh p n0" |
1952 |
and ns: "isnpolyh s n1" |
|
1953 |
and pnz: "p \<noteq> 0\<^sub>p" |
|
1954 |
shows "\<exists>k r. polydivide s p = (k, r) \<and> |
|
52803 | 1955 |
(\<exists>nr. isnpolyh r nr) \<and> (degree r = 0 \<or> degree r < degree p) \<and> |
56066 | 1956 |
(\<exists>q n1. isnpolyh q n1 \<and> polypow k (head p) *\<^sub>p s = p *\<^sub>p q +\<^sub>p r)" |
52803 | 1957 |
proof - |
1958 |
have trv: "head p = head p" "degree p = degree p" |
|
1959 |
by simp_all |
|
1960 |
from polydivide_def[where s="s" and p="p"] have ex: "\<exists> k r. polydivide s p = (k,r)" |
|
1961 |
by auto |
|
1962 |
then obtain k r where kr: "polydivide s p = (k,r)" |
|
1963 |
by blast |
|
56000 | 1964 |
from trans[OF polydivide_def[where s="s"and p="p", symmetric] kr] |
33154 | 1965 |
polydivide_aux_properties[OF np ns trv pnz, where k="0" and k'="k" and r="r"] |
1966 |
have "(degree r = 0 \<or> degree r < degree p) \<and> |
|
52803 | 1967 |
(\<exists>nr. isnpolyh r nr) \<and> (\<exists>q n1. isnpolyh q n1 \<and> head p ^\<^sub>p k - 0 *\<^sub>p s = p *\<^sub>p q +\<^sub>p r)" |
1968 |
by blast |
|
1969 |
with kr show ?thesis |
|
33154 | 1970 |
apply - |
1971 |
apply (rule exI[where x="k"]) |
|
1972 |
apply (rule exI[where x="r"]) |
|
1973 |
apply simp |
|
1974 |
done |
|
1975 |
qed |
|
1976 |
||
52658 | 1977 |
|
56066 | 1978 |
subsection {* More about polypoly and pnormal etc *} |
33154 | 1979 |
|
56000 | 1980 |
definition "isnonconstant p \<longleftrightarrow> \<not> isconstant p" |
33154 | 1981 |
|
52658 | 1982 |
lemma isnonconstant_pnormal_iff: |
56198 | 1983 |
assumes "isnonconstant p" |
52803 | 1984 |
shows "pnormal (polypoly bs p) \<longleftrightarrow> Ipoly bs (head p) \<noteq> 0" |
33154 | 1985 |
proof |
52803 | 1986 |
let ?p = "polypoly bs p" |
33154 | 1987 |
assume H: "pnormal ?p" |
56066 | 1988 |
have csz: "coefficients p \<noteq> []" |
56198 | 1989 |
using assms by (cases p) auto |
56066 | 1990 |
from coefficients_head[of p] last_map[OF csz, of "Ipoly bs"] pnormal_last_nonzero[OF H] |
1991 |
show "Ipoly bs (head p) \<noteq> 0" |
|
1992 |
by (simp add: polypoly_def) |
|
33154 | 1993 |
next |
1994 |
assume h: "\<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
|
1995 |
let ?p = "polypoly bs p" |
|
56066 | 1996 |
have csz: "coefficients p \<noteq> []" |
56198 | 1997 |
using assms by (cases p) auto |
56066 | 1998 |
then have pz: "?p \<noteq> []" |
1999 |
by (simp add: polypoly_def) |
|
2000 |
then have lg: "length ?p > 0" |
|
2001 |
by simp |
|
52803 | 2002 |
from h coefficients_head[of p] last_map[OF csz, of "Ipoly bs"] |
56066 | 2003 |
have lz: "last ?p \<noteq> 0" |
2004 |
by (simp add: polypoly_def) |
|
33154 | 2005 |
from pnormal_last_length[OF lg lz] show "pnormal ?p" . |
2006 |
qed |
|
2007 |
||
2008 |
lemma isnonconstant_coefficients_length: "isnonconstant p \<Longrightarrow> length (coefficients p) > 1" |
|
2009 |
unfolding isnonconstant_def |
|
52658 | 2010 |
apply (cases p) |
2011 |
apply simp_all |
|
58259 | 2012 |
apply (rename_tac nat a, case_tac nat) |
52658 | 2013 |
apply auto |
33154 | 2014 |
done |
52658 | 2015 |
|
2016 |
lemma isnonconstant_nonconstant: |
|
56198 | 2017 |
assumes "isnonconstant p" |
33154 | 2018 |
shows "nonconstant (polypoly bs p) \<longleftrightarrow> Ipoly bs (head p) \<noteq> 0" |
2019 |
proof |
|
2020 |
let ?p = "polypoly bs p" |
|
2021 |
assume nc: "nonconstant ?p" |
|
56198 | 2022 |
from isnonconstant_pnormal_iff[OF assms, of bs] nc |
56066 | 2023 |
show "\<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
2024 |
unfolding nonconstant_def by blast |
|
33154 | 2025 |
next |
2026 |
let ?p = "polypoly bs p" |
|
2027 |
assume h: "\<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
|
56198 | 2028 |
from isnonconstant_pnormal_iff[OF assms, of bs] h |
56066 | 2029 |
have pn: "pnormal ?p" |
2030 |
by blast |
|
56009 | 2031 |
{ |
2032 |
fix x |
|
2033 |
assume H: "?p = [x]" |
|
2034 |
from H have "length (coefficients p) = 1" |
|
2035 |
unfolding polypoly_def by auto |
|
56198 | 2036 |
with isnonconstant_coefficients_length[OF assms] |
2037 |
have False by arith |
|
56009 | 2038 |
} |
2039 |
then show "nonconstant ?p" |
|
2040 |
using pn unfolding nonconstant_def by blast |
|
33154 | 2041 |
qed |
2042 |
||
56066 | 2043 |
lemma pnormal_length: "p \<noteq> [] \<Longrightarrow> pnormal p \<longleftrightarrow> length (pnormalize p) = length p" |
52658 | 2044 |
apply (induct p) |
2045 |
apply (simp_all add: pnormal_def) |
|
2046 |
apply (case_tac "p = []") |
|
2047 |
apply simp_all |
|
2048 |
done |
|
33154 | 2049 |
|
52658 | 2050 |
lemma degree_degree: |
56207 | 2051 |
assumes "isnonconstant p" |
33154 | 2052 |
shows "degree p = Polynomial_List.degree (polypoly bs p) \<longleftrightarrow> \<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
2053 |
proof |
|
52803 | 2054 |
let ?p = "polypoly bs p" |
33154 | 2055 |
assume H: "degree p = Polynomial_List.degree ?p" |
56207 | 2056 |
from isnonconstant_coefficients_length[OF assms] have pz: "?p \<noteq> []" |
33154 | 2057 |
unfolding polypoly_def by auto |
56207 | 2058 |
from H degree_coefficients[of p] isnonconstant_coefficients_length[OF assms] |
56066 | 2059 |
have lg: "length (pnormalize ?p) = length ?p" |
33154 | 2060 |
unfolding Polynomial_List.degree_def polypoly_def by simp |
56066 | 2061 |
then have "pnormal ?p" |
2062 |
using pnormal_length[OF pz] by blast |
|
56207 | 2063 |
with isnonconstant_pnormal_iff[OF assms] show "\<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
56066 | 2064 |
by blast |
33154 | 2065 |
next |
56066 | 2066 |
let ?p = "polypoly bs p" |
33154 | 2067 |
assume H: "\<lparr>head p\<rparr>\<^sub>p\<^bsup>bs\<^esup> \<noteq> 0" |
56207 | 2068 |
with isnonconstant_pnormal_iff[OF assms] have "pnormal ?p" |
56066 | 2069 |
by blast |
56207 | 2070 |
with degree_coefficients[of p] isnonconstant_coefficients_length[OF assms] |
52803 | 2071 |
show "degree p = Polynomial_List.degree ?p" |
33154 | 2072 |
unfolding polypoly_def pnormal_def Polynomial_List.degree_def by auto |
2073 |
qed |
|
2074 |
||
52658 | 2075 |
|
52803 | 2076 |
section {* Swaps ; Division by a certain variable *} |
52658 | 2077 |
|
56066 | 2078 |
primrec swap :: "nat \<Rightarrow> nat \<Rightarrow> poly \<Rightarrow> poly" |
2079 |
where |
|
33154 | 2080 |
"swap n m (C x) = C x" |
56198 | 2081 |
| "swap n m (Bound k) = Bound (if k = n then m else if k = m then n else k)" |
39246 | 2082 |
| "swap n m (Neg t) = Neg (swap n m t)" |
2083 |
| "swap n m (Add s t) = Add (swap n m s) (swap n m t)" |
|
2084 |
| "swap n m (Sub s t) = Sub (swap n m s) (swap n m t)" |
|
2085 |
| "swap n m (Mul s t) = Mul (swap n m s) (swap n m t)" |
|
2086 |
| "swap n m (Pw t k) = Pw (swap n m t) k" |
|
56066 | 2087 |
| "swap n m (CN c k p) = CN (swap n m c) (if k = n then m else if k=m then n else k) (swap n m p)" |
33154 | 2088 |
|
52658 | 2089 |
lemma swap: |
56066 | 2090 |
assumes "n < length bs" |
2091 |
and "m < length bs" |
|
33154 | 2092 |
shows "Ipoly bs (swap n m t) = Ipoly ((bs[n:= bs!m])[m:= bs!n]) t" |
2093 |
proof (induct t) |
|
52658 | 2094 |
case (Bound k) |
56066 | 2095 |
then show ?case |
2096 |
using assms by simp |
|
33154 | 2097 |
next |
52658 | 2098 |
case (CN c k p) |
56066 | 2099 |
then show ?case |
2100 |
using assms by simp |
|
33154 | 2101 |
qed simp_all |
2102 |
||
52658 | 2103 |
lemma swap_swap_id [simp]: "swap n m (swap m n t) = t" |
2104 |
by (induct t) simp_all |
|
2105 |
||
2106 |
lemma swap_commute: "swap n m p = swap m n p" |
|
2107 |
by (induct p) simp_all |
|
33154 | 2108 |
|
2109 |
lemma swap_same_id[simp]: "swap n n t = t" |
|
52658 | 2110 |
by (induct t) simp_all |
33154 | 2111 |
|
2112 |
definition "swapnorm n m t = polynate (swap n m t)" |
|
2113 |
||
52658 | 2114 |
lemma swapnorm: |
2115 |
assumes nbs: "n < length bs" |
|
2116 |
and mbs: "m < length bs" |
|
56000 | 2117 |
shows "((Ipoly bs (swapnorm n m t) :: 'a::{field_char_0,field_inverse_zero})) = |
52658 | 2118 |
Ipoly ((bs[n:= bs!m])[m:= bs!n]) t" |
41807 | 2119 |
using swap[OF assms] swapnorm_def by simp |
33154 | 2120 |
|
52658 | 2121 |
lemma swapnorm_isnpoly [simp]: |
56000 | 2122 |
assumes "SORT_CONSTRAINT('a::{field_char_0,field_inverse_zero})" |
33154 | 2123 |
shows "isnpoly (swapnorm n m p)" |
2124 |
unfolding swapnorm_def by simp |
|
2125 |
||
52803 | 2126 |
definition "polydivideby n s p = |
56000 | 2127 |
(let |
2128 |
ss = swapnorm 0 n s; |
|
2129 |
sp = swapnorm 0 n p; |
|
2130 |
h = head sp; |
|
2131 |
(k, r) = polydivide ss sp |
|
2132 |
in (k, swapnorm 0 n h, swapnorm 0 n r))" |
|
33154 | 2133 |
|
56000 | 2134 |
lemma swap_nz [simp]: "swap n m p = 0\<^sub>p \<longleftrightarrow> p = 0\<^sub>p" |
52658 | 2135 |
by (induct p) simp_all |
33154 | 2136 |
|
41808 | 2137 |
fun isweaknpoly :: "poly \<Rightarrow> bool" |
2138 |
where |
|
33154 | 2139 |
"isweaknpoly (C c) = True" |
41808 | 2140 |
| "isweaknpoly (CN c n p) \<longleftrightarrow> isweaknpoly c \<and> isweaknpoly p" |
2141 |
| "isweaknpoly p = False" |
|
33154 | 2142 |
|
52803 | 2143 |
lemma isnpolyh_isweaknpoly: "isnpolyh p n0 \<Longrightarrow> isweaknpoly p" |
52658 | 2144 |
by (induct p arbitrary: n0) auto |
33154 | 2145 |
|
52803 | 2146 |
lemma swap_isweanpoly: "isweaknpoly p \<Longrightarrow> isweaknpoly (swap n m p)" |
52658 | 2147 |
by (induct p) auto |
33154 | 2148 |
|
2149 |
end |