author | wenzelm |
Sat, 24 Jun 2006 22:25:30 +0200 | |
changeset 19947 | 29b376397cd5 |
parent 16417 | 9bc16273c2d4 |
child 22814 | 4cd25f1706bb |
permissions | -rw-r--r-- |
5528 | 1 |
(* Title: ZF/ex/Bin.thy |
2 |
ID: $Id$ |
|
3 |
Author: Lawrence C Paulson, Cambridge University Computer Laboratory |
|
4 |
Copyright 1994 University of Cambridge |
|
5 |
||
6 |
The sign Pls stands for an infinite string of leading 0's. |
|
7 |
The sign Min stands for an infinite string of leading 1's. |
|
8 |
||
9 |
A number can have multiple representations, namely leading 0's with sign |
|
10 |
Pls and leading 1's with sign Min. See twos-compl.ML/int_of_binary for |
|
11 |
the numerical interpretation. |
|
12 |
||
13 |
The representation expects that (m mod 2) is 0 or 1, even if m is negative; |
|
14 |
For instance, ~5 div 2 = ~3 and ~5 mod 2 = 1; thus ~5 = (~3)*2 + 1 |
|
15 |
*) |
|
16 |
||
13560 | 17 |
header{*Arithmetic on Binary Integers*} |
18 |
||
16417 | 19 |
theory Bin imports Int Datatype begin |
5528 | 20 |
|
6117 | 21 |
consts bin :: i |
22 |
datatype |
|
23 |
"bin" = Pls |
|
24 |
| Min |
|
9570
e16e168984e1
installation of cancellation simprocs for the integers
paulson
parents:
9548
diff
changeset
|
25 |
| Bit ("w: bin", "b: bool") (infixl "BIT" 90) |
6117 | 26 |
|
27 |
syntax |
|
13560 | 28 |
"_Int" :: "xnum => i" ("_") |
6117 | 29 |
|
5528 | 30 |
consts |
13560 | 31 |
integ_of :: "i=>i" |
32 |
NCons :: "[i,i]=>i" |
|
33 |
bin_succ :: "i=>i" |
|
34 |
bin_pred :: "i=>i" |
|
35 |
bin_minus :: "i=>i" |
|
36 |
bin_adder :: "i=>i" |
|
37 |
bin_mult :: "[i,i]=>i" |
|
5528 | 38 |
|
6046 | 39 |
primrec |
13560 | 40 |
integ_of_Pls: "integ_of (Pls) = $# 0" |
41 |
integ_of_Min: "integ_of (Min) = $-($#1)" |
|
42 |
integ_of_BIT: "integ_of (w BIT b) = $#b $+ integ_of(w) $+ integ_of(w)" |
|
5528 | 43 |
|
44 |
(** recall that cond(1,b,c)=b and cond(0,b,c)=0 **) |
|
45 |
||
6046 | 46 |
primrec (*NCons adds a bit, suppressing leading 0s and 1s*) |
13560 | 47 |
NCons_Pls: "NCons (Pls,b) = cond(b,Pls BIT b,Pls)" |
48 |
NCons_Min: "NCons (Min,b) = cond(b,Min,Min BIT b)" |
|
49 |
NCons_BIT: "NCons (w BIT c,b) = w BIT c BIT b" |
|
5528 | 50 |
|
6153 | 51 |
primrec (*successor. If a BIT, can change a 0 to a 1 without recursion.*) |
13560 | 52 |
bin_succ_Pls: "bin_succ (Pls) = Pls BIT 1" |
53 |
bin_succ_Min: "bin_succ (Min) = Pls" |
|
54 |
bin_succ_BIT: "bin_succ (w BIT b) = cond(b, bin_succ(w) BIT 0, NCons(w,1))" |
|
5528 | 55 |
|
6046 | 56 |
primrec (*predecessor*) |
13560 | 57 |
bin_pred_Pls: "bin_pred (Pls) = Min" |
58 |
bin_pred_Min: "bin_pred (Min) = Min BIT 0" |
|
59 |
bin_pred_BIT: "bin_pred (w BIT b) = cond(b, NCons(w,0), bin_pred(w) BIT 1)" |
|
5528 | 60 |
|
6046 | 61 |
primrec (*unary negation*) |
13560 | 62 |
bin_minus_Pls: |
6046 | 63 |
"bin_minus (Pls) = Pls" |
13560 | 64 |
bin_minus_Min: |
6153 | 65 |
"bin_minus (Min) = Pls BIT 1" |
13560 | 66 |
bin_minus_BIT: |
6153 | 67 |
"bin_minus (w BIT b) = cond(b, bin_pred(NCons(bin_minus(w),0)), |
68 |
bin_minus(w) BIT 0)" |
|
6046 | 69 |
|
70 |
primrec (*sum*) |
|
13560 | 71 |
bin_adder_Pls: |
9207 | 72 |
"bin_adder (Pls) = (lam w:bin. w)" |
13560 | 73 |
bin_adder_Min: |
9207 | 74 |
"bin_adder (Min) = (lam w:bin. bin_pred(w))" |
13560 | 75 |
bin_adder_BIT: |
9207 | 76 |
"bin_adder (v BIT x) = |
77 |
(lam w:bin. |
|
78 |
bin_case (v BIT x, bin_pred(v BIT x), |
|
79 |
%w y. NCons(bin_adder (v) ` cond(x and y, bin_succ(w), w), |
|
80 |
x xor y), |
|
81 |
w))" |
|
5528 | 82 |
|
9207 | 83 |
(*The bin_case above replaces the following mutually recursive function: |
84 |
primrec |
|
6153 | 85 |
"adding (v,x,Pls) = v BIT x" |
86 |
"adding (v,x,Min) = bin_pred(v BIT x)" |
|
9207 | 87 |
"adding (v,x,w BIT y) = NCons(bin_adder (v, cond(x and y, bin_succ(w), w)), |
6153 | 88 |
x xor y)" |
9207 | 89 |
*) |
90 |
||
13560 | 91 |
constdefs |
92 |
bin_add :: "[i,i]=>i" |
|
93 |
"bin_add(v,w) == bin_adder(v)`w" |
|
9207 | 94 |
|
5528 | 95 |
|
6046 | 96 |
primrec |
13560 | 97 |
bin_mult_Pls: |
6153 | 98 |
"bin_mult (Pls,w) = Pls" |
13560 | 99 |
bin_mult_Min: |
6153 | 100 |
"bin_mult (Min,w) = bin_minus(w)" |
13560 | 101 |
bin_mult_BIT: |
6153 | 102 |
"bin_mult (v BIT b,w) = cond(b, bin_add(NCons(bin_mult(v,w),0),w), |
103 |
NCons(bin_mult(v,w),0))" |
|
6046 | 104 |
|
9570
e16e168984e1
installation of cancellation simprocs for the integers
paulson
parents:
9548
diff
changeset
|
105 |
setup NumeralSyntax.setup |
e16e168984e1
installation of cancellation simprocs for the integers
paulson
parents:
9548
diff
changeset
|
106 |
|
13560 | 107 |
|
108 |
declare bin.intros [simp,TC] |
|
109 |
||
110 |
lemma NCons_Pls_0: "NCons(Pls,0) = Pls" |
|
111 |
by simp |
|
112 |
||
113 |
lemma NCons_Pls_1: "NCons(Pls,1) = Pls BIT 1" |
|
114 |
by simp |
|
115 |
||
116 |
lemma NCons_Min_0: "NCons(Min,0) = Min BIT 0" |
|
117 |
by simp |
|
118 |
||
119 |
lemma NCons_Min_1: "NCons(Min,1) = Min" |
|
120 |
by simp |
|
121 |
||
122 |
lemma NCons_BIT: "NCons(w BIT x,b) = w BIT x BIT b" |
|
123 |
by (simp add: bin.case_eqns) |
|
124 |
||
125 |
lemmas NCons_simps [simp] = |
|
126 |
NCons_Pls_0 NCons_Pls_1 NCons_Min_0 NCons_Min_1 NCons_BIT |
|
127 |
||
128 |
||
129 |
||
130 |
(** Type checking **) |
|
131 |
||
132 |
lemma integ_of_type [TC]: "w: bin ==> integ_of(w) : int" |
|
133 |
apply (induct_tac "w") |
|
134 |
apply (simp_all add: bool_into_nat) |
|
135 |
done |
|
136 |
||
137 |
lemma NCons_type [TC]: "[| w: bin; b: bool |] ==> NCons(w,b) : bin" |
|
138 |
by (induct_tac "w", auto) |
|
139 |
||
140 |
lemma bin_succ_type [TC]: "w: bin ==> bin_succ(w) : bin" |
|
141 |
by (induct_tac "w", auto) |
|
142 |
||
143 |
lemma bin_pred_type [TC]: "w: bin ==> bin_pred(w) : bin" |
|
144 |
by (induct_tac "w", auto) |
|
145 |
||
146 |
lemma bin_minus_type [TC]: "w: bin ==> bin_minus(w) : bin" |
|
147 |
by (induct_tac "w", auto) |
|
148 |
||
149 |
(*This proof is complicated by the mutual recursion*) |
|
150 |
lemma bin_add_type [rule_format,TC]: |
|
151 |
"v: bin ==> ALL w: bin. bin_add(v,w) : bin" |
|
152 |
apply (unfold bin_add_def) |
|
153 |
apply (induct_tac "v") |
|
154 |
apply (rule_tac [3] ballI) |
|
155 |
apply (rename_tac [3] "w'") |
|
156 |
apply (induct_tac [3] "w'") |
|
157 |
apply (simp_all add: NCons_type) |
|
158 |
done |
|
159 |
||
160 |
lemma bin_mult_type [TC]: "[| v: bin; w: bin |] ==> bin_mult(v,w) : bin" |
|
161 |
by (induct_tac "v", auto) |
|
162 |
||
163 |
||
164 |
subsubsection{*The Carry and Borrow Functions, |
|
165 |
@{term bin_succ} and @{term bin_pred}*} |
|
166 |
||
167 |
(*NCons preserves the integer value of its argument*) |
|
168 |
lemma integ_of_NCons [simp]: |
|
169 |
"[| w: bin; b: bool |] ==> integ_of(NCons(w,b)) = integ_of(w BIT b)" |
|
170 |
apply (erule bin.cases) |
|
171 |
apply (auto elim!: boolE) |
|
172 |
done |
|
173 |
||
174 |
lemma integ_of_succ [simp]: |
|
175 |
"w: bin ==> integ_of(bin_succ(w)) = $#1 $+ integ_of(w)" |
|
176 |
apply (erule bin.induct) |
|
177 |
apply (auto simp add: zadd_ac elim!: boolE) |
|
178 |
done |
|
179 |
||
180 |
lemma integ_of_pred [simp]: |
|
181 |
"w: bin ==> integ_of(bin_pred(w)) = $- ($#1) $+ integ_of(w)" |
|
182 |
apply (erule bin.induct) |
|
183 |
apply (auto simp add: zadd_ac elim!: boolE) |
|
184 |
done |
|
185 |
||
186 |
||
187 |
subsubsection{*@{term bin_minus}: Unary Negation of Binary Integers*} |
|
188 |
||
189 |
lemma integ_of_minus: "w: bin ==> integ_of(bin_minus(w)) = $- integ_of(w)" |
|
190 |
apply (erule bin.induct) |
|
191 |
apply (auto simp add: zadd_ac zminus_zadd_distrib elim!: boolE) |
|
192 |
done |
|
193 |
||
194 |
||
195 |
subsubsection{*@{term bin_add}: Binary Addition*} |
|
196 |
||
197 |
lemma bin_add_Pls [simp]: "w: bin ==> bin_add(Pls,w) = w" |
|
198 |
by (unfold bin_add_def, simp) |
|
199 |
||
200 |
lemma bin_add_Pls_right: "w: bin ==> bin_add(w,Pls) = w" |
|
201 |
apply (unfold bin_add_def) |
|
202 |
apply (erule bin.induct, auto) |
|
203 |
done |
|
204 |
||
205 |
lemma bin_add_Min [simp]: "w: bin ==> bin_add(Min,w) = bin_pred(w)" |
|
206 |
by (unfold bin_add_def, simp) |
|
207 |
||
208 |
lemma bin_add_Min_right: "w: bin ==> bin_add(w,Min) = bin_pred(w)" |
|
209 |
apply (unfold bin_add_def) |
|
210 |
apply (erule bin.induct, auto) |
|
211 |
done |
|
212 |
||
213 |
lemma bin_add_BIT_Pls [simp]: "bin_add(v BIT x,Pls) = v BIT x" |
|
214 |
by (unfold bin_add_def, simp) |
|
215 |
||
216 |
lemma bin_add_BIT_Min [simp]: "bin_add(v BIT x,Min) = bin_pred(v BIT x)" |
|
217 |
by (unfold bin_add_def, simp) |
|
218 |
||
219 |
lemma bin_add_BIT_BIT [simp]: |
|
220 |
"[| w: bin; y: bool |] |
|
221 |
==> bin_add(v BIT x, w BIT y) = |
|
222 |
NCons(bin_add(v, cond(x and y, bin_succ(w), w)), x xor y)" |
|
223 |
by (unfold bin_add_def, simp) |
|
224 |
||
225 |
lemma integ_of_add [rule_format]: |
|
226 |
"v: bin ==> |
|
227 |
ALL w: bin. integ_of(bin_add(v,w)) = integ_of(v) $+ integ_of(w)" |
|
228 |
apply (erule bin.induct, simp, simp) |
|
229 |
apply (rule ballI) |
|
230 |
apply (induct_tac "wa") |
|
231 |
apply (auto simp add: zadd_ac elim!: boolE) |
|
232 |
done |
|
233 |
||
234 |
(*Subtraction*) |
|
235 |
lemma diff_integ_of_eq: |
|
236 |
"[| v: bin; w: bin |] |
|
237 |
==> integ_of(v) $- integ_of(w) = integ_of(bin_add (v, bin_minus(w)))" |
|
238 |
apply (unfold zdiff_def) |
|
239 |
apply (simp add: integ_of_add integ_of_minus) |
|
240 |
done |
|
241 |
||
242 |
||
243 |
subsubsection{*@{term bin_mult}: Binary Multiplication*} |
|
244 |
||
245 |
lemma integ_of_mult: |
|
246 |
"[| v: bin; w: bin |] |
|
247 |
==> integ_of(bin_mult(v,w)) = integ_of(v) $* integ_of(w)" |
|
248 |
apply (induct_tac "v", simp) |
|
249 |
apply (simp add: integ_of_minus) |
|
250 |
apply (auto simp add: zadd_ac integ_of_add zadd_zmult_distrib elim!: boolE) |
|
251 |
done |
|
252 |
||
253 |
||
254 |
subsection{*Computations*} |
|
255 |
||
256 |
(** extra rules for bin_succ, bin_pred **) |
|
257 |
||
258 |
lemma bin_succ_1: "bin_succ(w BIT 1) = bin_succ(w) BIT 0" |
|
259 |
by simp |
|
260 |
||
261 |
lemma bin_succ_0: "bin_succ(w BIT 0) = NCons(w,1)" |
|
262 |
by simp |
|
263 |
||
264 |
lemma bin_pred_1: "bin_pred(w BIT 1) = NCons(w,0)" |
|
265 |
by simp |
|
266 |
||
267 |
lemma bin_pred_0: "bin_pred(w BIT 0) = bin_pred(w) BIT 1" |
|
268 |
by simp |
|
269 |
||
270 |
(** extra rules for bin_minus **) |
|
271 |
||
272 |
lemma bin_minus_1: "bin_minus(w BIT 1) = bin_pred(NCons(bin_minus(w), 0))" |
|
273 |
by simp |
|
274 |
||
275 |
lemma bin_minus_0: "bin_minus(w BIT 0) = bin_minus(w) BIT 0" |
|
276 |
by simp |
|
277 |
||
278 |
(** extra rules for bin_add **) |
|
279 |
||
280 |
lemma bin_add_BIT_11: "w: bin ==> bin_add(v BIT 1, w BIT 1) = |
|
281 |
NCons(bin_add(v, bin_succ(w)), 0)" |
|
282 |
by simp |
|
283 |
||
284 |
lemma bin_add_BIT_10: "w: bin ==> bin_add(v BIT 1, w BIT 0) = |
|
285 |
NCons(bin_add(v,w), 1)" |
|
286 |
by simp |
|
287 |
||
288 |
lemma bin_add_BIT_0: "[| w: bin; y: bool |] |
|
289 |
==> bin_add(v BIT 0, w BIT y) = NCons(bin_add(v,w), y)" |
|
290 |
by simp |
|
291 |
||
292 |
(** extra rules for bin_mult **) |
|
293 |
||
294 |
lemma bin_mult_1: "bin_mult(v BIT 1, w) = bin_add(NCons(bin_mult(v,w),0), w)" |
|
295 |
by simp |
|
296 |
||
297 |
lemma bin_mult_0: "bin_mult(v BIT 0, w) = NCons(bin_mult(v,w),0)" |
|
298 |
by simp |
|
299 |
||
300 |
||
301 |
(** Simplification rules with integer constants **) |
|
302 |
||
303 |
lemma int_of_0: "$#0 = #0" |
|
304 |
by simp |
|
305 |
||
306 |
lemma int_of_succ: "$# succ(n) = #1 $+ $#n" |
|
307 |
by (simp add: int_of_add [symmetric] natify_succ) |
|
308 |
||
309 |
lemma zminus_0 [simp]: "$- #0 = #0" |
|
310 |
by simp |
|
311 |
||
312 |
lemma zadd_0_intify [simp]: "#0 $+ z = intify(z)" |
|
313 |
by simp |
|
314 |
||
315 |
lemma zadd_0_right_intify [simp]: "z $+ #0 = intify(z)" |
|
316 |
by simp |
|
317 |
||
318 |
lemma zmult_1_intify [simp]: "#1 $* z = intify(z)" |
|
319 |
by simp |
|
320 |
||
321 |
lemma zmult_1_right_intify [simp]: "z $* #1 = intify(z)" |
|
322 |
by (subst zmult_commute, simp) |
|
323 |
||
324 |
lemma zmult_0 [simp]: "#0 $* z = #0" |
|
325 |
by simp |
|
326 |
||
327 |
lemma zmult_0_right [simp]: "z $* #0 = #0" |
|
328 |
by (subst zmult_commute, simp) |
|
329 |
||
330 |
lemma zmult_minus1 [simp]: "#-1 $* z = $-z" |
|
331 |
by (simp add: zcompare_rls) |
|
332 |
||
333 |
lemma zmult_minus1_right [simp]: "z $* #-1 = $-z" |
|
334 |
apply (subst zmult_commute) |
|
335 |
apply (rule zmult_minus1) |
|
336 |
done |
|
337 |
||
338 |
||
339 |
subsection{*Simplification Rules for Comparison of Binary Numbers*} |
|
340 |
text{*Thanks to Norbert Voelker*} |
|
341 |
||
342 |
(** Equals (=) **) |
|
343 |
||
344 |
lemma eq_integ_of_eq: |
|
345 |
"[| v: bin; w: bin |] |
|
346 |
==> ((integ_of(v)) = integ_of(w)) <-> |
|
347 |
iszero (integ_of (bin_add (v, bin_minus(w))))" |
|
348 |
apply (unfold iszero_def) |
|
349 |
apply (simp add: zcompare_rls integ_of_add integ_of_minus) |
|
350 |
done |
|
351 |
||
352 |
lemma iszero_integ_of_Pls: "iszero (integ_of(Pls))" |
|
353 |
by (unfold iszero_def, simp) |
|
354 |
||
355 |
||
356 |
lemma nonzero_integ_of_Min: "~ iszero (integ_of(Min))" |
|
357 |
apply (unfold iszero_def) |
|
358 |
apply (simp add: zminus_equation) |
|
359 |
done |
|
360 |
||
361 |
lemma iszero_integ_of_BIT: |
|
362 |
"[| w: bin; x: bool |] |
|
363 |
==> iszero (integ_of (w BIT x)) <-> (x=0 & iszero (integ_of(w)))" |
|
364 |
apply (unfold iszero_def, simp) |
|
365 |
apply (subgoal_tac "integ_of (w) : int") |
|
366 |
apply typecheck |
|
367 |
apply (drule int_cases) |
|
13612 | 368 |
apply (safe elim!: boolE) |
369 |
apply (simp_all (asm_lr) add: zcompare_rls zminus_zadd_distrib [symmetric] |
|
13560 | 370 |
int_of_add [symmetric]) |
371 |
done |
|
372 |
||
373 |
lemma iszero_integ_of_0: |
|
374 |
"w: bin ==> iszero (integ_of (w BIT 0)) <-> iszero (integ_of(w))" |
|
375 |
by (simp only: iszero_integ_of_BIT, blast) |
|
376 |
||
377 |
lemma iszero_integ_of_1: "w: bin ==> ~ iszero (integ_of (w BIT 1))" |
|
378 |
by (simp only: iszero_integ_of_BIT, blast) |
|
379 |
||
380 |
||
381 |
||
382 |
(** Less-than (<) **) |
|
383 |
||
384 |
lemma less_integ_of_eq_neg: |
|
385 |
"[| v: bin; w: bin |] |
|
386 |
==> integ_of(v) $< integ_of(w) |
|
387 |
<-> znegative (integ_of (bin_add (v, bin_minus(w))))" |
|
388 |
apply (unfold zless_def zdiff_def) |
|
389 |
apply (simp add: integ_of_minus integ_of_add) |
|
390 |
done |
|
391 |
||
392 |
lemma not_neg_integ_of_Pls: "~ znegative (integ_of(Pls))" |
|
393 |
by simp |
|
394 |
||
395 |
lemma neg_integ_of_Min: "znegative (integ_of(Min))" |
|
396 |
by simp |
|
397 |
||
398 |
lemma neg_integ_of_BIT: |
|
399 |
"[| w: bin; x: bool |] |
|
400 |
==> znegative (integ_of (w BIT x)) <-> znegative (integ_of(w))" |
|
401 |
apply simp |
|
402 |
apply (subgoal_tac "integ_of (w) : int") |
|
403 |
apply typecheck |
|
404 |
apply (drule int_cases) |
|
405 |
apply (auto elim!: boolE simp add: int_of_add [symmetric] zcompare_rls) |
|
406 |
apply (simp_all add: zminus_zadd_distrib [symmetric] zdiff_def |
|
407 |
int_of_add [symmetric]) |
|
408 |
apply (subgoal_tac "$#1 $- $# succ (succ (n #+ n)) = $- $# succ (n #+ n) ") |
|
409 |
apply (simp add: zdiff_def) |
|
410 |
apply (simp add: equation_zminus int_of_diff [symmetric]) |
|
411 |
done |
|
412 |
||
413 |
(** Less-than-or-equals (<=) **) |
|
414 |
||
415 |
lemma le_integ_of_eq_not_less: |
|
416 |
"(integ_of(x) $<= (integ_of(w))) <-> ~ (integ_of(w) $< (integ_of(x)))" |
|
417 |
by (simp add: not_zless_iff_zle [THEN iff_sym]) |
|
418 |
||
419 |
||
420 |
(*Delete the original rewrites, with their clumsy conditional expressions*) |
|
421 |
declare bin_succ_BIT [simp del] |
|
422 |
bin_pred_BIT [simp del] |
|
423 |
bin_minus_BIT [simp del] |
|
424 |
NCons_Pls [simp del] |
|
425 |
NCons_Min [simp del] |
|
426 |
bin_adder_BIT [simp del] |
|
427 |
bin_mult_BIT [simp del] |
|
428 |
||
429 |
(*Hide the binary representation of integer constants*) |
|
430 |
declare integ_of_Pls [simp del] integ_of_Min [simp del] integ_of_BIT [simp del] |
|
431 |
||
432 |
||
433 |
lemmas bin_arith_extra_simps = |
|
434 |
integ_of_add [symmetric] |
|
435 |
integ_of_minus [symmetric] |
|
436 |
integ_of_mult [symmetric] |
|
437 |
bin_succ_1 bin_succ_0 |
|
438 |
bin_pred_1 bin_pred_0 |
|
439 |
bin_minus_1 bin_minus_0 |
|
440 |
bin_add_Pls_right bin_add_Min_right |
|
441 |
bin_add_BIT_0 bin_add_BIT_10 bin_add_BIT_11 |
|
442 |
diff_integ_of_eq |
|
443 |
bin_mult_1 bin_mult_0 NCons_simps |
|
444 |
||
445 |
||
446 |
(*For making a minimal simpset, one must include these default simprules |
|
447 |
of thy. Also include simp_thms, or at least (~False)=True*) |
|
448 |
lemmas bin_arith_simps = |
|
449 |
bin_pred_Pls bin_pred_Min |
|
450 |
bin_succ_Pls bin_succ_Min |
|
451 |
bin_add_Pls bin_add_Min |
|
452 |
bin_minus_Pls bin_minus_Min |
|
453 |
bin_mult_Pls bin_mult_Min |
|
454 |
bin_arith_extra_simps |
|
455 |
||
456 |
(*Simplification of relational operations*) |
|
457 |
lemmas bin_rel_simps = |
|
458 |
eq_integ_of_eq iszero_integ_of_Pls nonzero_integ_of_Min |
|
459 |
iszero_integ_of_0 iszero_integ_of_1 |
|
460 |
less_integ_of_eq_neg |
|
461 |
not_neg_integ_of_Pls neg_integ_of_Min neg_integ_of_BIT |
|
462 |
le_integ_of_eq_not_less |
|
463 |
||
464 |
declare bin_arith_simps [simp] |
|
465 |
declare bin_rel_simps [simp] |
|
466 |
||
467 |
||
468 |
(** Simplification of arithmetic when nested to the right **) |
|
469 |
||
470 |
lemma add_integ_of_left [simp]: |
|
471 |
"[| v: bin; w: bin |] |
|
472 |
==> integ_of(v) $+ (integ_of(w) $+ z) = (integ_of(bin_add(v,w)) $+ z)" |
|
473 |
by (simp add: zadd_assoc [symmetric]) |
|
474 |
||
475 |
lemma mult_integ_of_left [simp]: |
|
476 |
"[| v: bin; w: bin |] |
|
477 |
==> integ_of(v) $* (integ_of(w) $* z) = (integ_of(bin_mult(v,w)) $* z)" |
|
478 |
by (simp add: zmult_assoc [symmetric]) |
|
479 |
||
480 |
lemma add_integ_of_diff1 [simp]: |
|
481 |
"[| v: bin; w: bin |] |
|
482 |
==> integ_of(v) $+ (integ_of(w) $- c) = integ_of(bin_add(v,w)) $- (c)" |
|
483 |
apply (unfold zdiff_def) |
|
484 |
apply (rule add_integ_of_left, auto) |
|
485 |
done |
|
486 |
||
487 |
lemma add_integ_of_diff2 [simp]: |
|
488 |
"[| v: bin; w: bin |] |
|
489 |
==> integ_of(v) $+ (c $- integ_of(w)) = |
|
490 |
integ_of (bin_add (v, bin_minus(w))) $+ (c)" |
|
491 |
apply (subst diff_integ_of_eq [symmetric]) |
|
492 |
apply (simp_all add: zdiff_def zadd_ac) |
|
493 |
done |
|
494 |
||
495 |
||
496 |
(** More for integer constants **) |
|
497 |
||
498 |
declare int_of_0 [simp] int_of_succ [simp] |
|
499 |
||
500 |
lemma zdiff0 [simp]: "#0 $- x = $-x" |
|
501 |
by (simp add: zdiff_def) |
|
502 |
||
503 |
lemma zdiff0_right [simp]: "x $- #0 = intify(x)" |
|
504 |
by (simp add: zdiff_def) |
|
505 |
||
506 |
lemma zdiff_self [simp]: "x $- x = #0" |
|
507 |
by (simp add: zdiff_def) |
|
508 |
||
509 |
lemma znegative_iff_zless_0: "k: int ==> znegative(k) <-> k $< #0" |
|
510 |
by (simp add: zless_def) |
|
511 |
||
512 |
lemma zero_zless_imp_znegative_zminus: "[|#0 $< k; k: int|] ==> znegative($-k)" |
|
513 |
by (simp add: zless_def) |
|
514 |
||
515 |
lemma zero_zle_int_of [simp]: "#0 $<= $# n" |
|
516 |
by (simp add: not_zless_iff_zle [THEN iff_sym] znegative_iff_zless_0 [THEN iff_sym]) |
|
517 |
||
518 |
lemma nat_of_0 [simp]: "nat_of(#0) = 0" |
|
519 |
by (simp only: natify_0 int_of_0 [symmetric] nat_of_int_of) |
|
520 |
||
521 |
lemma nat_le_int0_lemma: "[| z $<= $#0; z: int |] ==> nat_of(z) = 0" |
|
522 |
by (auto simp add: znegative_iff_zless_0 [THEN iff_sym] zle_def zneg_nat_of) |
|
523 |
||
524 |
lemma nat_le_int0: "z $<= $#0 ==> nat_of(z) = 0" |
|
525 |
apply (subgoal_tac "nat_of (intify (z)) = 0") |
|
526 |
apply (rule_tac [2] nat_le_int0_lemma, auto) |
|
527 |
done |
|
528 |
||
529 |
lemma int_of_eq_0_imp_natify_eq_0: "$# n = #0 ==> natify(n) = 0" |
|
530 |
by (rule not_znegative_imp_zero, auto) |
|
531 |
||
532 |
lemma nat_of_zminus_int_of: "nat_of($- $# n) = 0" |
|
14511 | 533 |
by (simp add: nat_of_def int_of_def raw_nat_of zminus image_intrel_int) |
13560 | 534 |
|
535 |
lemma int_of_nat_of: "#0 $<= z ==> $# nat_of(z) = intify(z)" |
|
536 |
apply (rule not_zneg_nat_of_intify) |
|
537 |
apply (simp add: znegative_iff_zless_0 not_zless_iff_zle) |
|
538 |
done |
|
539 |
||
540 |
declare int_of_nat_of [simp] nat_of_zminus_int_of [simp] |
|
541 |
||
542 |
lemma int_of_nat_of_if: "$# nat_of(z) = (if #0 $<= z then intify(z) else #0)" |
|
543 |
by (simp add: int_of_nat_of znegative_iff_zless_0 not_zle_iff_zless) |
|
544 |
||
545 |
lemma zless_nat_iff_int_zless: "[| m: nat; z: int |] ==> (m < nat_of(z)) <-> ($#m $< z)" |
|
546 |
apply (case_tac "znegative (z) ") |
|
547 |
apply (erule_tac [2] not_zneg_nat_of [THEN subst]) |
|
548 |
apply (auto dest: zless_trans dest!: zero_zle_int_of [THEN zle_zless_trans] |
|
549 |
simp add: znegative_iff_zless_0) |
|
550 |
done |
|
551 |
||
552 |
||
553 |
(** nat_of and zless **) |
|
554 |
||
555 |
(*An alternative condition is $#0 <= w *) |
|
556 |
lemma zless_nat_conj_lemma: "$#0 $< z ==> (nat_of(w) < nat_of(z)) <-> (w $< z)" |
|
557 |
apply (rule iff_trans) |
|
558 |
apply (rule zless_int_of [THEN iff_sym]) |
|
559 |
apply (auto simp add: int_of_nat_of_if simp del: zless_int_of) |
|
560 |
apply (auto elim: zless_asym simp add: not_zle_iff_zless) |
|
561 |
apply (blast intro: zless_zle_trans) |
|
562 |
done |
|
563 |
||
564 |
lemma zless_nat_conj: "(nat_of(w) < nat_of(z)) <-> ($#0 $< z & w $< z)" |
|
565 |
apply (case_tac "$#0 $< z") |
|
566 |
apply (auto simp add: zless_nat_conj_lemma nat_le_int0 not_zless_iff_zle) |
|
567 |
done |
|
568 |
||
569 |
(*This simprule cannot be added unless we can find a way to make eq_integ_of_eq |
|
570 |
unconditional! |
|
571 |
[The condition "True" is a hack to prevent looping. |
|
572 |
Conditional rewrite rules are tried after unconditional ones, so a rule |
|
573 |
like eq_nat_number_of will be tried first to eliminate #mm=#nn.] |
|
574 |
lemma integ_of_reorient [simp]: |
|
575 |
"True ==> (integ_of(w) = x) <-> (x = integ_of(w))" |
|
576 |
by auto |
|
577 |
*) |
|
578 |
||
579 |
lemma integ_of_minus_reorient [simp]: |
|
580 |
"(integ_of(w) = $- x) <-> ($- x = integ_of(w))" |
|
581 |
by auto |
|
582 |
||
583 |
lemma integ_of_add_reorient [simp]: |
|
584 |
"(integ_of(w) = x $+ y) <-> (x $+ y = integ_of(w))" |
|
585 |
by auto |
|
586 |
||
587 |
lemma integ_of_diff_reorient [simp]: |
|
588 |
"(integ_of(w) = x $- y) <-> (x $- y = integ_of(w))" |
|
589 |
by auto |
|
590 |
||
591 |
lemma integ_of_mult_reorient [simp]: |
|
592 |
"(integ_of(w) = x $* y) <-> (x $* y = integ_of(w))" |
|
593 |
by auto |
|
594 |
||
595 |
ML |
|
596 |
{* |
|
597 |
val bin_pred_Pls = thm "bin_pred_Pls"; |
|
598 |
val bin_pred_Min = thm "bin_pred_Min"; |
|
599 |
val bin_minus_Pls = thm "bin_minus_Pls"; |
|
600 |
val bin_minus_Min = thm "bin_minus_Min"; |
|
601 |
||
602 |
val NCons_Pls_0 = thm "NCons_Pls_0"; |
|
603 |
val NCons_Pls_1 = thm "NCons_Pls_1"; |
|
604 |
val NCons_Min_0 = thm "NCons_Min_0"; |
|
605 |
val NCons_Min_1 = thm "NCons_Min_1"; |
|
606 |
val NCons_BIT = thm "NCons_BIT"; |
|
607 |
val NCons_simps = thms "NCons_simps"; |
|
608 |
val integ_of_type = thm "integ_of_type"; |
|
609 |
val NCons_type = thm "NCons_type"; |
|
610 |
val bin_succ_type = thm "bin_succ_type"; |
|
611 |
val bin_pred_type = thm "bin_pred_type"; |
|
612 |
val bin_minus_type = thm "bin_minus_type"; |
|
613 |
val bin_add_type = thm "bin_add_type"; |
|
614 |
val bin_mult_type = thm "bin_mult_type"; |
|
615 |
val integ_of_NCons = thm "integ_of_NCons"; |
|
616 |
val integ_of_succ = thm "integ_of_succ"; |
|
617 |
val integ_of_pred = thm "integ_of_pred"; |
|
618 |
val integ_of_minus = thm "integ_of_minus"; |
|
619 |
val bin_add_Pls = thm "bin_add_Pls"; |
|
620 |
val bin_add_Pls_right = thm "bin_add_Pls_right"; |
|
621 |
val bin_add_Min = thm "bin_add_Min"; |
|
622 |
val bin_add_Min_right = thm "bin_add_Min_right"; |
|
623 |
val bin_add_BIT_Pls = thm "bin_add_BIT_Pls"; |
|
624 |
val bin_add_BIT_Min = thm "bin_add_BIT_Min"; |
|
625 |
val bin_add_BIT_BIT = thm "bin_add_BIT_BIT"; |
|
626 |
val integ_of_add = thm "integ_of_add"; |
|
627 |
val diff_integ_of_eq = thm "diff_integ_of_eq"; |
|
628 |
val integ_of_mult = thm "integ_of_mult"; |
|
629 |
val bin_succ_1 = thm "bin_succ_1"; |
|
630 |
val bin_succ_0 = thm "bin_succ_0"; |
|
631 |
val bin_pred_1 = thm "bin_pred_1"; |
|
632 |
val bin_pred_0 = thm "bin_pred_0"; |
|
633 |
val bin_minus_1 = thm "bin_minus_1"; |
|
634 |
val bin_minus_0 = thm "bin_minus_0"; |
|
635 |
val bin_add_BIT_11 = thm "bin_add_BIT_11"; |
|
636 |
val bin_add_BIT_10 = thm "bin_add_BIT_10"; |
|
637 |
val bin_add_BIT_0 = thm "bin_add_BIT_0"; |
|
638 |
val bin_mult_1 = thm "bin_mult_1"; |
|
639 |
val bin_mult_0 = thm "bin_mult_0"; |
|
640 |
val int_of_0 = thm "int_of_0"; |
|
641 |
val int_of_succ = thm "int_of_succ"; |
|
642 |
val zminus_0 = thm "zminus_0"; |
|
643 |
val zadd_0_intify = thm "zadd_0_intify"; |
|
644 |
val zadd_0_right_intify = thm "zadd_0_right_intify"; |
|
645 |
val zmult_1_intify = thm "zmult_1_intify"; |
|
646 |
val zmult_1_right_intify = thm "zmult_1_right_intify"; |
|
647 |
val zmult_0 = thm "zmult_0"; |
|
648 |
val zmult_0_right = thm "zmult_0_right"; |
|
649 |
val zmult_minus1 = thm "zmult_minus1"; |
|
650 |
val zmult_minus1_right = thm "zmult_minus1_right"; |
|
651 |
val eq_integ_of_eq = thm "eq_integ_of_eq"; |
|
652 |
val iszero_integ_of_Pls = thm "iszero_integ_of_Pls"; |
|
653 |
val nonzero_integ_of_Min = thm "nonzero_integ_of_Min"; |
|
654 |
val iszero_integ_of_BIT = thm "iszero_integ_of_BIT"; |
|
655 |
val iszero_integ_of_0 = thm "iszero_integ_of_0"; |
|
656 |
val iszero_integ_of_1 = thm "iszero_integ_of_1"; |
|
657 |
val less_integ_of_eq_neg = thm "less_integ_of_eq_neg"; |
|
658 |
val not_neg_integ_of_Pls = thm "not_neg_integ_of_Pls"; |
|
659 |
val neg_integ_of_Min = thm "neg_integ_of_Min"; |
|
660 |
val neg_integ_of_BIT = thm "neg_integ_of_BIT"; |
|
661 |
val le_integ_of_eq_not_less = thm "le_integ_of_eq_not_less"; |
|
662 |
val bin_arith_extra_simps = thms "bin_arith_extra_simps"; |
|
663 |
val bin_arith_simps = thms "bin_arith_simps"; |
|
664 |
val bin_rel_simps = thms "bin_rel_simps"; |
|
665 |
val add_integ_of_left = thm "add_integ_of_left"; |
|
666 |
val mult_integ_of_left = thm "mult_integ_of_left"; |
|
667 |
val add_integ_of_diff1 = thm "add_integ_of_diff1"; |
|
668 |
val add_integ_of_diff2 = thm "add_integ_of_diff2"; |
|
669 |
val zdiff0 = thm "zdiff0"; |
|
670 |
val zdiff0_right = thm "zdiff0_right"; |
|
671 |
val zdiff_self = thm "zdiff_self"; |
|
672 |
val znegative_iff_zless_0 = thm "znegative_iff_zless_0"; |
|
673 |
val zero_zless_imp_znegative_zminus = thm "zero_zless_imp_znegative_zminus"; |
|
674 |
val zero_zle_int_of = thm "zero_zle_int_of"; |
|
675 |
val nat_of_0 = thm "nat_of_0"; |
|
676 |
val nat_le_int0 = thm "nat_le_int0"; |
|
677 |
val int_of_eq_0_imp_natify_eq_0 = thm "int_of_eq_0_imp_natify_eq_0"; |
|
678 |
val nat_of_zminus_int_of = thm "nat_of_zminus_int_of"; |
|
679 |
val int_of_nat_of = thm "int_of_nat_of"; |
|
680 |
val int_of_nat_of_if = thm "int_of_nat_of_if"; |
|
681 |
val zless_nat_iff_int_zless = thm "zless_nat_iff_int_zless"; |
|
682 |
val zless_nat_conj = thm "zless_nat_conj"; |
|
683 |
val integ_of_minus_reorient = thm "integ_of_minus_reorient"; |
|
684 |
val integ_of_add_reorient = thm "integ_of_add_reorient"; |
|
685 |
val integ_of_diff_reorient = thm "integ_of_diff_reorient"; |
|
686 |
val integ_of_mult_reorient = thm "integ_of_mult_reorient"; |
|
687 |
*} |
|
688 |
||
5528 | 689 |
end |