--- a/src/HOL/Tools/int_arith.ML Fri May 08 08:01:09 2009 +0200
+++ b/src/HOL/Tools/int_arith.ML Fri May 08 09:48:07 2009 +0200
@@ -1,420 +1,15 @@
-(* Authors: Larry Paulson and Tobias Nipkow
-
-Simprocs and decision procedure for numerals and linear arithmetic.
-*)
-
-structure Int_Numeral_Simprocs =
-struct
-
-(** Utilities **)
-
-fun mk_number T n = HOLogic.number_of_const T $ HOLogic.mk_numeral n;
-
-fun find_first_numeral past (t::terms) =
- ((snd (HOLogic.dest_number t), rev past @ terms)
- handle TERM _ => find_first_numeral (t::past) terms)
- | find_first_numeral past [] = raise TERM("find_first_numeral", []);
-
-val mk_plus = HOLogic.mk_binop @{const_name HOL.plus};
-
-fun mk_minus t =
- let val T = Term.fastype_of t
- in Const (@{const_name HOL.uminus}, T --> T) $ t end;
-
-(*Thus mk_sum[t] yields t+0; longer sums don't have a trailing zero*)
-fun mk_sum T [] = mk_number T 0
- | mk_sum T [t,u] = mk_plus (t, u)
- | mk_sum T (t :: ts) = mk_plus (t, mk_sum T ts);
-
-(*this version ALWAYS includes a trailing zero*)
-fun long_mk_sum T [] = mk_number T 0
- | long_mk_sum T (t :: ts) = mk_plus (t, mk_sum T ts);
-
-val dest_plus = HOLogic.dest_bin @{const_name HOL.plus} Term.dummyT;
-
-(*decompose additions AND subtractions as a sum*)
-fun dest_summing (pos, Const (@{const_name HOL.plus}, _) $ t $ u, ts) =
- dest_summing (pos, t, dest_summing (pos, u, ts))
- | dest_summing (pos, Const (@{const_name HOL.minus}, _) $ t $ u, ts) =
- dest_summing (pos, t, dest_summing (not pos, u, ts))
- | dest_summing (pos, t, ts) =
- if pos then t::ts else mk_minus t :: ts;
-
-fun dest_sum t = dest_summing (true, t, []);
-
-val mk_diff = HOLogic.mk_binop @{const_name HOL.minus};
-val dest_diff = HOLogic.dest_bin @{const_name HOL.minus} Term.dummyT;
-
-val mk_times = HOLogic.mk_binop @{const_name HOL.times};
-
-fun one_of T = Const(@{const_name HOL.one},T);
-
-(* build product with trailing 1 rather than Numeral 1 in order to avoid the
- unnecessary restriction to type class number_ring
- which is not required for cancellation of common factors in divisions.
-*)
-fun mk_prod T =
- let val one = one_of T
- fun mk [] = one
- | mk [t] = t
- | mk (t :: ts) = if t = one then mk ts else mk_times (t, mk ts)
- in mk end;
-
-(*This version ALWAYS includes a trailing one*)
-fun long_mk_prod T [] = one_of T
- | long_mk_prod T (t :: ts) = mk_times (t, mk_prod T ts);
-
-val dest_times = HOLogic.dest_bin @{const_name HOL.times} Term.dummyT;
-
-fun dest_prod t =
- let val (t,u) = dest_times t
- in dest_prod t @ dest_prod u end
- handle TERM _ => [t];
-
-(*DON'T do the obvious simplifications; that would create special cases*)
-fun mk_coeff (k, t) = mk_times (mk_number (Term.fastype_of t) k, t);
-
-(*Express t as a product of (possibly) a numeral with other sorted terms*)
-fun dest_coeff sign (Const (@{const_name HOL.uminus}, _) $ t) = dest_coeff (~sign) t
- | dest_coeff sign t =
- let val ts = sort TermOrd.term_ord (dest_prod t)
- val (n, ts') = find_first_numeral [] ts
- handle TERM _ => (1, ts)
- in (sign*n, mk_prod (Term.fastype_of t) ts') end;
-
-(*Find first coefficient-term THAT MATCHES u*)
-fun find_first_coeff past u [] = raise TERM("find_first_coeff", [])
- | find_first_coeff past u (t::terms) =
- let val (n,u') = dest_coeff 1 t
- in if u aconv u' then (n, rev past @ terms)
- else find_first_coeff (t::past) u terms
- end
- handle TERM _ => find_first_coeff (t::past) u terms;
-
-(*Fractions as pairs of ints. Can't use Rat.rat because the representation
- needs to preserve negative values in the denominator.*)
-fun mk_frac (p, q) = if q = 0 then raise Div else (p, q);
-
-(*Don't reduce fractions; sums must be proved by rule add_frac_eq.
- Fractions are reduced later by the cancel_numeral_factor simproc.*)
-fun add_frac ((p1, q1), (p2, q2)) = (p1 * q2 + p2 * q1, q1 * q2);
-
-val mk_divide = HOLogic.mk_binop @{const_name HOL.divide};
-
-(*Build term (p / q) * t*)
-fun mk_fcoeff ((p, q), t) =
- let val T = Term.fastype_of t
- in mk_times (mk_divide (mk_number T p, mk_number T q), t) end;
-
-(*Express t as a product of a fraction with other sorted terms*)
-fun dest_fcoeff sign (Const (@{const_name HOL.uminus}, _) $ t) = dest_fcoeff (~sign) t
- | dest_fcoeff sign (Const (@{const_name HOL.divide}, _) $ t $ u) =
- let val (p, t') = dest_coeff sign t
- val (q, u') = dest_coeff 1 u
- in (mk_frac (p, q), mk_divide (t', u')) end
- | dest_fcoeff sign t =
- let val (p, t') = dest_coeff sign t
- val T = Term.fastype_of t
- in (mk_frac (p, 1), mk_divide (t', one_of T)) end;
-
-
-(** New term ordering so that AC-rewriting brings numerals to the front **)
-
-(*Order integers by absolute value and then by sign. The standard integer
- ordering is not well-founded.*)
-fun num_ord (i,j) =
- (case int_ord (abs i, abs j) of
- EQUAL => int_ord (Int.sign i, Int.sign j)
- | ord => ord);
-
-(*This resembles TermOrd.term_ord, but it puts binary numerals before other
- non-atomic terms.*)
-local open Term
-in
-fun numterm_ord (Abs (_, T, t), Abs(_, U, u)) =
- (case numterm_ord (t, u) of EQUAL => TermOrd.typ_ord (T, U) | ord => ord)
- | numterm_ord
- (Const(@{const_name Int.number_of}, _) $ v, Const(@{const_name Int.number_of}, _) $ w) =
- num_ord (HOLogic.dest_numeral v, HOLogic.dest_numeral w)
- | numterm_ord (Const(@{const_name Int.number_of}, _) $ _, _) = LESS
- | numterm_ord (_, Const(@{const_name Int.number_of}, _) $ _) = GREATER
- | numterm_ord (t, u) =
- (case int_ord (size_of_term t, size_of_term u) of
- EQUAL =>
- let val (f, ts) = strip_comb t and (g, us) = strip_comb u in
- (case TermOrd.hd_ord (f, g) of EQUAL => numterms_ord (ts, us) | ord => ord)
- end
- | ord => ord)
-and numterms_ord (ts, us) = list_ord numterm_ord (ts, us)
-end;
-
-fun numtermless tu = (numterm_ord tu = LESS);
-
-val num_ss = HOL_ss settermless numtermless;
-
-(*Maps 0 to Numeral0 and 1 to Numeral1 so that arithmetic isn't complicated by the abstract 0 and 1.*)
-val numeral_syms = [@{thm numeral_0_eq_0} RS sym, @{thm numeral_1_eq_1} RS sym];
-
-(*Simplify Numeral0+n, n+Numeral0, Numeral1*n, n*Numeral1, 1*x, x*1, x/1 *)
-val add_0s = @{thms add_0s};
-val mult_1s = @{thms mult_1s mult_1_left mult_1_right divide_1};
-
-(*Simplify inverse Numeral1, a/Numeral1*)
-val inverse_1s = [@{thm inverse_numeral_1}];
-val divide_1s = [@{thm divide_numeral_1}];
-
-(*To perform binary arithmetic. The "left" rewriting handles patterns
- created by the Int_Numeral_Simprocs, such as 3 * (5 * x). *)
-val simps = [@{thm numeral_0_eq_0} RS sym, @{thm numeral_1_eq_1} RS sym,
- @{thm add_number_of_left}, @{thm mult_number_of_left}] @
- @{thms arith_simps} @ @{thms rel_simps};
-
-(*Binary arithmetic BUT NOT ADDITION since it may collapse adjacent terms
- during re-arrangement*)
-val non_add_simps =
- subtract Thm.eq_thm [@{thm add_number_of_left}, @{thm number_of_add} RS sym] simps;
-
-(*To evaluate binary negations of coefficients*)
-val minus_simps = [@{thm numeral_m1_eq_minus_1} RS sym, @{thm number_of_minus} RS sym] @
- @{thms minus_bin_simps} @ @{thms pred_bin_simps};
-
-(*To let us treat subtraction as addition*)
-val diff_simps = [@{thm diff_minus}, @{thm minus_add_distrib}, @{thm minus_minus}];
-
-(*To let us treat division as multiplication*)
-val divide_simps = [@{thm divide_inverse}, @{thm inverse_mult_distrib}, @{thm inverse_inverse_eq}];
-
-(*push the unary minus down: - x * y = x * - y *)
-val minus_mult_eq_1_to_2 =
- [@{thm mult_minus_left}, @{thm minus_mult_right}] MRS trans |> standard;
-
-(*to extract again any uncancelled minuses*)
-val minus_from_mult_simps =
- [@{thm minus_minus}, @{thm mult_minus_left}, @{thm mult_minus_right}];
-
-(*combine unary minus with numeric literals, however nested within a product*)
-val mult_minus_simps =
- [@{thm mult_assoc}, @{thm minus_mult_left}, minus_mult_eq_1_to_2];
-
-val norm_ss1 = num_ss addsimps numeral_syms @ add_0s @ mult_1s @
- diff_simps @ minus_simps @ @{thms add_ac}
-val norm_ss2 = num_ss addsimps non_add_simps @ mult_minus_simps
-val norm_ss3 = num_ss addsimps minus_from_mult_simps @ @{thms add_ac} @ @{thms mult_ac}
+(* Author: Tobias Nipkow
-structure CancelNumeralsCommon =
- struct
- val mk_sum = mk_sum
- val dest_sum = dest_sum
- val mk_coeff = mk_coeff
- val dest_coeff = dest_coeff 1
- val find_first_coeff = find_first_coeff []
- val trans_tac = K Arith_Data.trans_tac
-
- fun norm_tac ss =
- ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
-
- val numeral_simp_ss = HOL_ss addsimps add_0s @ simps
- fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
- val simplify_meta_eq = Arith_Data.simplify_meta_eq (add_0s @ mult_1s)
- end;
-
-
-structure EqCancelNumerals = CancelNumeralsFun
- (open CancelNumeralsCommon
- val prove_conv = Arith_Data.prove_conv
- val mk_bal = HOLogic.mk_eq
- val dest_bal = HOLogic.dest_bin "op =" Term.dummyT
- val bal_add1 = @{thm eq_add_iff1} RS trans
- val bal_add2 = @{thm eq_add_iff2} RS trans
-);
-
-structure LessCancelNumerals = CancelNumeralsFun
- (open CancelNumeralsCommon
- val prove_conv = Arith_Data.prove_conv
- val mk_bal = HOLogic.mk_binrel @{const_name HOL.less}
- val dest_bal = HOLogic.dest_bin @{const_name HOL.less} Term.dummyT
- val bal_add1 = @{thm less_add_iff1} RS trans
- val bal_add2 = @{thm less_add_iff2} RS trans
-);
-
-structure LeCancelNumerals = CancelNumeralsFun
- (open CancelNumeralsCommon
- val prove_conv = Arith_Data.prove_conv
- val mk_bal = HOLogic.mk_binrel @{const_name HOL.less_eq}
- val dest_bal = HOLogic.dest_bin @{const_name HOL.less_eq} Term.dummyT
- val bal_add1 = @{thm le_add_iff1} RS trans
- val bal_add2 = @{thm le_add_iff2} RS trans
-);
-
-val cancel_numerals =
- map Arith_Data.prep_simproc
- [("inteq_cancel_numerals",
- ["(l::'a::number_ring) + m = n",
- "(l::'a::number_ring) = m + n",
- "(l::'a::number_ring) - m = n",
- "(l::'a::number_ring) = m - n",
- "(l::'a::number_ring) * m = n",
- "(l::'a::number_ring) = m * n"],
- K EqCancelNumerals.proc),
- ("intless_cancel_numerals",
- ["(l::'a::{ordered_idom,number_ring}) + m < n",
- "(l::'a::{ordered_idom,number_ring}) < m + n",
- "(l::'a::{ordered_idom,number_ring}) - m < n",
- "(l::'a::{ordered_idom,number_ring}) < m - n",
- "(l::'a::{ordered_idom,number_ring}) * m < n",
- "(l::'a::{ordered_idom,number_ring}) < m * n"],
- K LessCancelNumerals.proc),
- ("intle_cancel_numerals",
- ["(l::'a::{ordered_idom,number_ring}) + m <= n",
- "(l::'a::{ordered_idom,number_ring}) <= m + n",
- "(l::'a::{ordered_idom,number_ring}) - m <= n",
- "(l::'a::{ordered_idom,number_ring}) <= m - n",
- "(l::'a::{ordered_idom,number_ring}) * m <= n",
- "(l::'a::{ordered_idom,number_ring}) <= m * n"],
- K LeCancelNumerals.proc)];
-
-
-structure CombineNumeralsData =
- struct
- type coeff = int
- val iszero = (fn x => x = 0)
- val add = op +
- val mk_sum = long_mk_sum (*to work for e.g. 2*x + 3*x *)
- val dest_sum = dest_sum
- val mk_coeff = mk_coeff
- val dest_coeff = dest_coeff 1
- val left_distrib = @{thm combine_common_factor} RS trans
- val prove_conv = Arith_Data.prove_conv_nohyps
- val trans_tac = K Arith_Data.trans_tac
-
- fun norm_tac ss =
- ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
-
- val numeral_simp_ss = HOL_ss addsimps add_0s @ simps
- fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
- val simplify_meta_eq = Arith_Data.simplify_meta_eq (add_0s @ mult_1s)
- end;
-
-structure CombineNumerals = CombineNumeralsFun(CombineNumeralsData);
-
-(*Version for fields, where coefficients can be fractions*)
-structure FieldCombineNumeralsData =
- struct
- type coeff = int * int
- val iszero = (fn (p, q) => p = 0)
- val add = add_frac
- val mk_sum = long_mk_sum
- val dest_sum = dest_sum
- val mk_coeff = mk_fcoeff
- val dest_coeff = dest_fcoeff 1
- val left_distrib = @{thm combine_common_factor} RS trans
- val prove_conv = Arith_Data.prove_conv_nohyps
- val trans_tac = K Arith_Data.trans_tac
-
- val norm_ss1a = norm_ss1 addsimps inverse_1s @ divide_simps
- fun norm_tac ss =
- ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1a))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
- THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
-
- val numeral_simp_ss = HOL_ss addsimps add_0s @ simps @ [@{thm add_frac_eq}]
- fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
- val simplify_meta_eq = Arith_Data.simplify_meta_eq (add_0s @ mult_1s @ divide_1s)
- end;
-
-structure FieldCombineNumerals = CombineNumeralsFun(FieldCombineNumeralsData);
-
-val combine_numerals =
- Arith_Data.prep_simproc
- ("int_combine_numerals",
- ["(i::'a::number_ring) + j", "(i::'a::number_ring) - j"],
- K CombineNumerals.proc);
-
-val field_combine_numerals =
- Arith_Data.prep_simproc
- ("field_combine_numerals",
- ["(i::'a::{number_ring,field,division_by_zero}) + j",
- "(i::'a::{number_ring,field,division_by_zero}) - j"],
- K FieldCombineNumerals.proc);
-
-(** Constant folding for multiplication in semirings **)
-
-(*We do not need folding for addition: combine_numerals does the same thing*)
-
-structure Semiring_Times_Assoc_Data : ASSOC_FOLD_DATA =
-struct
- val assoc_ss = HOL_ss addsimps @{thms mult_ac}
- val eq_reflection = eq_reflection
- fun is_numeral (Const(@{const_name Int.number_of}, _) $ _) = true
- | is_numeral _ = false;
-end;
-
-structure Semiring_Times_Assoc = Assoc_Fold (Semiring_Times_Assoc_Data);
-
-val assoc_fold_simproc =
- Arith_Data.prep_simproc
- ("semiring_assoc_fold", ["(a::'a::comm_semiring_1_cancel) * b"],
- K Semiring_Times_Assoc.proc);
-
-end;
-
-Addsimprocs Int_Numeral_Simprocs.cancel_numerals;
-Addsimprocs [Int_Numeral_Simprocs.combine_numerals];
-Addsimprocs [Int_Numeral_Simprocs.field_combine_numerals];
-Addsimprocs [Int_Numeral_Simprocs.assoc_fold_simproc];
-
-(*examples:
-print_depth 22;
-set timing;
-set trace_simp;
-fun test s = (Goal s, by (Simp_tac 1));
-
-test "l + 2 + 2 + 2 + (l + 2) + (oo + 2) = (uu::int)";
-
-test "2*u = (u::int)";
-test "(i + j + 12 + (k::int)) - 15 = y";
-test "(i + j + 12 + (k::int)) - 5 = y";
-
-test "y - b < (b::int)";
-test "y - (3*b + c) < (b::int) - 2*c";
-
-test "(2*x - (u*v) + y) - v*3*u = (w::int)";
-test "(2*x*u*v + (u*v)*4 + y) - v*u*4 = (w::int)";
-test "(2*x*u*v + (u*v)*4 + y) - v*u = (w::int)";
-test "u*v - (x*u*v + (u*v)*4 + y) = (w::int)";
-
-test "(i + j + 12 + (k::int)) = u + 15 + y";
-test "(i + j*2 + 12 + (k::int)) = j + 5 + y";
-
-test "2*y + 3*z + 6*w + 2*y + 3*z + 2*u = 2*y' + 3*z' + 6*w' + 2*y' + 3*z' + u + (vv::int)";
-
-test "a + -(b+c) + b = (d::int)";
-test "a + -(b+c) - b = (d::int)";
-
-(*negative numerals*)
-test "(i + j + -2 + (k::int)) - (u + 5 + y) = zz";
-test "(i + j + -3 + (k::int)) < u + 5 + y";
-test "(i + j + 3 + (k::int)) < u + -6 + y";
-test "(i + j + -12 + (k::int)) - 15 = y";
-test "(i + j + 12 + (k::int)) - -15 = y";
-test "(i + j + -12 + (k::int)) - -15 = y";
-*)
-
-(*** decision procedure for linear arithmetic ***)
-
-(*---------------------------------------------------------------------------*)
-(* Linear arithmetic *)
-(*---------------------------------------------------------------------------*)
-
-(*
Instantiation of the generic linear arithmetic package for int.
*)
-structure Int_Arith =
+signature INT_ARITH =
+sig
+ val fast_int_arith_simproc: simproc
+ val setup: Context.generic -> Context.generic
+end
+
+structure Int_Arith : INT_ARITH =
struct
(* Update parameters of arithmetic prover *)
@@ -491,9 +86,9 @@
val nat_inj_thms = [@{thm zle_int} RS iffD2, @{thm int_int_eq} RS iffD2]
-val int_numeral_base_simprocs = Int_Numeral_Simprocs.assoc_fold_simproc :: zero_one_idom_simproc
- :: Int_Numeral_Simprocs.combine_numerals
- :: Int_Numeral_Simprocs.cancel_numerals;
+val numeral_base_simprocs = Numeral_Simprocs.assoc_fold_simproc :: zero_one_idom_simproc
+ :: Numeral_Simprocs.combine_numerals
+ :: Numeral_Simprocs.cancel_numerals;
val setup =
Lin_Arith.map_data (fn {add_mono_thms, mult_mono_thms, inj_thms, lessD, neqE, simpset} =>
@@ -503,7 +98,7 @@
lessD = lessD @ [@{thm zless_imp_add1_zle}],
neqE = neqE,
simpset = simpset addsimps add_rules
- addsimprocs int_numeral_base_simprocs
+ addsimprocs numeral_base_simprocs
addcongs [if_weak_cong]}) #>
arith_inj_const (@{const_name of_nat}, HOLogic.natT --> HOLogic.intT) #>
arith_discrete @{type_name Int.int}