src/HOL/Matrix/ComputeNumeral.thy
changeset 32491 d5d8bea0cd94
parent 29804 e15b74577368
child 33343 2eb0b672ab40
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Matrix/ComputeNumeral.thy	Wed Sep 02 16:25:44 2009 +0200
@@ -0,0 +1,195 @@
+theory ComputeNumeral
+imports ComputeHOL ComputeFloat
+begin
+
+(* normalization of bit strings *)
+lemmas bitnorm = normalize_bin_simps
+
+(* neg for bit strings *)
+lemma neg1: "neg Int.Pls = False" by (simp add: Int.Pls_def)
+lemma neg2: "neg Int.Min = True" apply (subst Int.Min_def) by auto
+lemma neg3: "neg (Int.Bit0 x) = neg x" apply (simp add: neg_def) apply (subst Bit0_def) by auto
+lemma neg4: "neg (Int.Bit1 x) = neg x" apply (simp add: neg_def) apply (subst Bit1_def) by auto  
+lemmas bitneg = neg1 neg2 neg3 neg4
+
+(* iszero for bit strings *)
+lemma iszero1: "iszero Int.Pls = True" by (simp add: Int.Pls_def iszero_def)
+lemma iszero2: "iszero Int.Min = False" apply (subst Int.Min_def) apply (subst iszero_def) by simp
+lemma iszero3: "iszero (Int.Bit0 x) = iszero x" apply (subst Int.Bit0_def) apply (subst iszero_def)+ by auto
+lemma iszero4: "iszero (Int.Bit1 x) = False" apply (subst Int.Bit1_def) apply (subst iszero_def)+  apply simp by arith
+lemmas bitiszero = iszero1 iszero2 iszero3 iszero4
+
+(* lezero for bit strings *)
+constdefs
+  "lezero x == (x \<le> 0)"
+lemma lezero1: "lezero Int.Pls = True" unfolding Int.Pls_def lezero_def by auto
+lemma lezero2: "lezero Int.Min = True" unfolding Int.Min_def lezero_def by auto
+lemma lezero3: "lezero (Int.Bit0 x) = lezero x" unfolding Int.Bit0_def lezero_def by auto
+lemma lezero4: "lezero (Int.Bit1 x) = neg x" unfolding Int.Bit1_def lezero_def neg_def by auto
+lemmas bitlezero = lezero1 lezero2 lezero3 lezero4
+
+(* equality for bit strings *)
+lemmas biteq = eq_bin_simps
+
+(* x < y for bit strings *)
+lemmas bitless = less_bin_simps
+
+(* x \<le> y for bit strings *)
+lemmas bitle = le_bin_simps
+
+(* succ for bit strings *)
+lemmas bitsucc = succ_bin_simps
+
+(* pred for bit strings *)
+lemmas bitpred = pred_bin_simps
+
+(* unary minus for bit strings *)
+lemmas bituminus = minus_bin_simps
+
+(* addition for bit strings *)
+lemmas bitadd = add_bin_simps
+
+(* multiplication for bit strings *) 
+lemma mult_Pls_right: "x * Int.Pls = Int.Pls" by (simp add: Pls_def)
+lemma mult_Min_right: "x * Int.Min = - x" by (subst mult_commute, simp add: mult_Min)
+lemma multb0x: "(Int.Bit0 x) * y = Int.Bit0 (x * y)" by (rule mult_Bit0)
+lemma multxb0: "x * (Int.Bit0 y) = Int.Bit0 (x * y)" unfolding Bit0_def by simp
+lemma multb1: "(Int.Bit1 x) * (Int.Bit1 y) = Int.Bit1 (Int.Bit0 (x * y) + x + y)"
+  unfolding Bit0_def Bit1_def by (simp add: algebra_simps)
+lemmas bitmul = mult_Pls mult_Min mult_Pls_right mult_Min_right multb0x multxb0 multb1
+
+lemmas bitarith = bitnorm bitiszero bitneg bitlezero biteq bitless bitle bitsucc bitpred bituminus bitadd bitmul 
+
+constdefs 
+  "nat_norm_number_of (x::nat) == x"
+
+lemma nat_norm_number_of: "nat_norm_number_of (number_of w) = (if lezero w then 0 else number_of w)"
+  apply (simp add: nat_norm_number_of_def)
+  unfolding lezero_def iszero_def neg_def
+  apply (simp add: numeral_simps)
+  done
+
+(* Normalization of nat literals *)
+lemma natnorm0: "(0::nat) = number_of (Int.Pls)" by auto
+lemma natnorm1: "(1 :: nat) = number_of (Int.Bit1 Int.Pls)"  by auto 
+lemmas natnorm = natnorm0 natnorm1 nat_norm_number_of
+
+(* Suc *)
+lemma natsuc: "Suc (number_of x) = (if neg x then 1 else number_of (Int.succ x))" by (auto simp add: number_of_is_id)
+
+(* Addition for nat *)
+lemma natadd: "number_of x + ((number_of y)::nat) = (if neg x then (number_of y) else (if neg y then number_of x else (number_of (x + y))))"
+  unfolding nat_number_of_def number_of_is_id neg_def
+  by auto
+
+(* Subtraction for nat *)
+lemma natsub: "(number_of x) - ((number_of y)::nat) = 
+  (if neg x then 0 else (if neg y then number_of x else (nat_norm_number_of (number_of (x + (- y))))))"
+  unfolding nat_norm_number_of
+  by (auto simp add: number_of_is_id neg_def lezero_def iszero_def Let_def nat_number_of_def)
+
+(* Multiplication for nat *)
+lemma natmul: "(number_of x) * ((number_of y)::nat) = 
+  (if neg x then 0 else (if neg y then 0 else number_of (x * y)))"
+  unfolding nat_number_of_def number_of_is_id neg_def
+  by (simp add: nat_mult_distrib)
+
+lemma nateq: "(((number_of x)::nat) = (number_of y)) = ((lezero x \<and> lezero y) \<or> (x = y))"
+  by (auto simp add: iszero_def lezero_def neg_def number_of_is_id)
+
+lemma natless: "(((number_of x)::nat) < (number_of y)) = ((x < y) \<and> (\<not> (lezero y)))"
+  by (simp add: lezero_def numeral_simps not_le)
+
+lemma natle: "(((number_of x)::nat) \<le> (number_of y)) = (y < x \<longrightarrow> lezero x)"
+  by (auto simp add: number_of_is_id lezero_def nat_number_of_def)
+
+fun natfac :: "nat \<Rightarrow> nat"
+where
+   "natfac n = (if n = 0 then 1 else n * (natfac (n - 1)))"
+
+lemmas compute_natarith = bitarith natnorm natsuc natadd natsub natmul nateq natless natle natfac.simps
+
+lemma number_eq: "(((number_of x)::'a::{number_ring, ordered_idom}) = (number_of y)) = (x = y)"
+  unfolding number_of_eq
+  apply simp
+  done
+
+lemma number_le: "(((number_of x)::'a::{number_ring, ordered_idom}) \<le>  (number_of y)) = (x \<le> y)"
+  unfolding number_of_eq
+  apply simp
+  done
+
+lemma number_less: "(((number_of x)::'a::{number_ring, ordered_idom}) <  (number_of y)) = (x < y)"
+  unfolding number_of_eq 
+  apply simp
+  done
+
+lemma number_diff: "((number_of x)::'a::{number_ring, ordered_idom}) - number_of y = number_of (x + (- y))"
+  apply (subst diff_number_of_eq)
+  apply simp
+  done
+
+lemmas number_norm = number_of_Pls[symmetric] numeral_1_eq_1[symmetric]
+
+lemmas compute_numberarith = number_of_minus[symmetric] number_of_add[symmetric] number_diff number_of_mult[symmetric] number_norm number_eq number_le number_less
+
+lemma compute_real_of_nat_number_of: "real ((number_of v)::nat) = (if neg v then 0 else number_of v)"
+  by (simp only: real_of_nat_number_of number_of_is_id)
+
+lemma compute_nat_of_int_number_of: "nat ((number_of v)::int) = (number_of v)"
+  by simp
+
+lemmas compute_num_conversions = compute_real_of_nat_number_of compute_nat_of_int_number_of real_number_of
+
+lemmas zpowerarith = zpower_number_of_even
+  zpower_number_of_odd[simplified zero_eq_Numeral0_nring one_eq_Numeral1_nring]
+  zpower_Pls zpower_Min
+
+(* div, mod *)
+
+lemma adjust: "adjust b (q, r) = (if 0 \<le> r - b then (2 * q + 1, r - b) else (2 * q, r))"
+  by (auto simp only: adjust_def)
+
+lemma negateSnd: "negateSnd (q, r) = (q, -r)" 
+  by (simp add: negateSnd_def)
+
+lemma divmod: "IntDiv.divmod a b = (if 0\<le>a then
+                  if 0\<le>b then posDivAlg a b
+                  else if a=0 then (0, 0)
+                       else negateSnd (negDivAlg (-a) (-b))
+               else 
+                  if 0<b then negDivAlg a b
+                  else negateSnd (posDivAlg (-a) (-b)))"
+  by (auto simp only: IntDiv.divmod_def)
+
+lemmas compute_div_mod = div_def mod_def divmod adjust negateSnd posDivAlg.simps negDivAlg.simps
+
+
+
+(* collecting all the theorems *)
+
+lemma even_Pls: "even (Int.Pls) = True"
+  apply (unfold Pls_def even_def)
+  by simp
+
+lemma even_Min: "even (Int.Min) = False"
+  apply (unfold Min_def even_def)
+  by simp
+
+lemma even_B0: "even (Int.Bit0 x) = True"
+  apply (unfold Bit0_def)
+  by simp
+
+lemma even_B1: "even (Int.Bit1 x) = False"
+  apply (unfold Bit1_def)
+  by simp
+
+lemma even_number_of: "even ((number_of w)::int) = even w"
+  by (simp only: number_of_is_id)
+
+lemmas compute_even = even_Pls even_Min even_B0 even_B1 even_number_of
+
+lemmas compute_numeral = compute_if compute_let compute_pair compute_bool 
+                         compute_natarith compute_numberarith max_def min_def compute_num_conversions zpowerarith compute_div_mod compute_even
+
+end