(* Title: HOL/Real/RealBin.ML
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1999 University of Cambridge
Binary arithmetic for the reals (integer literals only).
*)
(** real (coercion from int to real) **)
Goal "real (number_of w :: int) = number_of w";
by (simp_tac (simpset() addsimps [real_number_of_def]) 1);
qed "real_number_of";
Addsimps [real_number_of];
Goalw [real_number_of_def] "Numeral0 = (0::real)";
by (simp_tac (simpset() addsimps [real_of_int_zero RS sym]) 1);
qed "real_numeral_0_eq_0";
Goalw [real_number_of_def] "Numeral1 = (1::real)";
by (stac (real_of_one RS sym) 1);
by (Simp_tac 1);
qed "real_numeral_1_eq_1";
(** Addition **)
Goal "(number_of v :: real) + number_of v' = number_of (bin_add v v')";
by (simp_tac
(HOL_ss addsimps [real_number_of_def,
real_of_int_add, number_of_add]) 1);
qed "add_real_number_of";
Addsimps [add_real_number_of];
(** Subtraction **)
Goalw [real_number_of_def] "- (number_of w :: real) = number_of (bin_minus w)";
by (simp_tac
(HOL_ss addsimps [number_of_minus, real_of_int_minus]) 1);
qed "minus_real_number_of";
Goalw [real_number_of_def]
"(number_of v :: real) - number_of w = number_of (bin_add v (bin_minus w))";
by (simp_tac
(HOL_ss addsimps [diff_number_of_eq, real_of_int_diff]) 1);
qed "diff_real_number_of";
Addsimps [minus_real_number_of, diff_real_number_of];
(** Multiplication **)
Goal "(number_of v :: real) * number_of v' = number_of (bin_mult v v')";
by (simp_tac
(HOL_ss addsimps [real_number_of_def, real_of_int_mult,
number_of_mult]) 1);
qed "mult_real_number_of";
Addsimps [mult_real_number_of];
Goal "(2::real) = 1 + 1";
by (simp_tac (simpset() addsimps [real_numeral_1_eq_1 RS sym]) 1);
val lemma = result();
(*For specialist use: NOT as default simprules*)
Goal "2 * z = (z+z::real)";
by (simp_tac (simpset () addsimps [lemma, real_add_mult_distrib]) 1);
qed "real_mult_2";
Goal "z * 2 = (z+z::real)";
by (stac real_mult_commute 1 THEN rtac real_mult_2 1);
qed "real_mult_2_right";
(*** Comparisons ***)
(** Equals (=) **)
Goal "((number_of v :: real) = number_of v') = \
\ iszero (number_of (bin_add v (bin_minus v')))";
by (simp_tac
(HOL_ss addsimps [real_number_of_def,
real_of_int_inject, eq_number_of_eq]) 1);
qed "eq_real_number_of";
Addsimps [eq_real_number_of];
(** Less-than (<) **)
(*"neg" is used in rewrite rules for binary comparisons*)
Goal "((number_of v :: real) < number_of v') = \
\ neg (number_of (bin_add v (bin_minus v')))";
by (simp_tac
(HOL_ss addsimps [real_number_of_def, real_of_int_less_iff,
less_number_of_eq_neg]) 1);
qed "less_real_number_of";
Addsimps [less_real_number_of];
(** Less-than-or-equals (<=) **)
Goal "(number_of x <= (number_of y::real)) = \
\ (~ number_of y < (number_of x::real))";
by (rtac (linorder_not_less RS sym) 1);
qed "le_real_number_of_eq_not_less";
Addsimps [le_real_number_of_eq_not_less];
(*** New versions of existing theorems involving 0, 1 ***)
Goal "- 1 = (-1::real)";
by (simp_tac (simpset() addsimps [real_numeral_1_eq_1 RS sym]) 1);
qed "real_minus_1_eq_m1";
Goal "-1 * z = -(z::real)";
by (simp_tac (simpset() addsimps [real_minus_1_eq_m1 RS sym,
real_mult_minus_1]) 1);
qed "real_mult_minus1";
Goal "z * -1 = -(z::real)";
by (stac real_mult_commute 1 THEN rtac real_mult_minus1 1);
qed "real_mult_minus1_right";
Addsimps [real_mult_minus1, real_mult_minus1_right];
(*Maps 0 to Numeral0 and 1 to Numeral1 and -(Numeral1) to -1*)
val real_numeral_ss =
HOL_ss addsimps [real_numeral_0_eq_0 RS sym, real_numeral_1_eq_1 RS sym,
real_minus_1_eq_m1];
fun rename_numerals th =
asm_full_simplify real_numeral_ss (Thm.transfer (the_context ()) th);
(** real from type "nat" **)
Goal "(0 < real (n::nat)) = (0<n)";
by (simp_tac (HOL_ss addsimps [real_of_nat_less_iff,
real_of_nat_zero RS sym]) 1);
qed "zero_less_real_of_nat_iff";
AddIffs [zero_less_real_of_nat_iff];
Goal "(0 <= real (n::nat)) = (0<=n)";
by (simp_tac (HOL_ss addsimps [real_of_nat_le_iff,
real_of_nat_zero RS sym]) 1);
qed "zero_le_real_of_nat_iff";
AddIffs [zero_le_real_of_nat_iff];
(*Like the ones above, for "equals"*)
AddIffs [real_of_nat_zero_iff];
(** Simplification of arithmetic when nested to the right **)
Goal "number_of v + (number_of w + z) = (number_of(bin_add v w) + z::real)";
by Auto_tac;
qed "real_add_number_of_left";
Goal "number_of v * (number_of w * z) = (number_of(bin_mult v w) * z::real)";
by (simp_tac (simpset() addsimps [real_mult_assoc RS sym]) 1);
qed "real_mult_number_of_left";
Goalw [real_diff_def]
"number_of v + (number_of w - c) = number_of(bin_add v w) - (c::real)";
by (rtac real_add_number_of_left 1);
qed "real_add_number_of_diff1";
Goal "number_of v + (c - number_of w) = \
\ number_of (bin_add v (bin_minus w)) + (c::real)";
by (stac (diff_real_number_of RS sym) 1);
by Auto_tac;
qed "real_add_number_of_diff2";
Addsimps [real_add_number_of_left, real_mult_number_of_left,
real_add_number_of_diff1, real_add_number_of_diff2];
(*"neg" is used in rewrite rules for binary comparisons*)
Goal "real (number_of v :: nat) = \
\ (if neg (number_of v) then 0 \
\ else (number_of v :: real))";
by (simp_tac
(HOL_ss addsimps [nat_number_of_def, real_of_nat_real_of_int,
real_of_nat_neg_int, real_number_of,
real_numeral_0_eq_0 RS sym]) 1);
qed "real_of_nat_number_of";
Addsimps [real_of_nat_number_of];
(**** Simprocs for numeric literals ****)
(** Combining of literal coefficients in sums of products **)
Goal "(x < y) = (x-y < (0::real))";
by (simp_tac (simpset() addsimps [real_diff_less_eq]) 1);
qed "real_less_iff_diff_less_0";
Goal "(x = y) = (x-y = (0::real))";
by (simp_tac (simpset() addsimps [real_diff_eq_eq]) 1);
qed "real_eq_iff_diff_eq_0";
Goal "(x <= y) = (x-y <= (0::real))";
by (simp_tac (simpset() addsimps [real_diff_le_eq]) 1);
qed "real_le_iff_diff_le_0";
(** For combine_numerals **)
Goal "i*u + (j*u + k) = (i+j)*u + (k::real)";
by (asm_simp_tac (simpset() addsimps [real_add_mult_distrib]) 1);
qed "left_real_add_mult_distrib";
(** For cancel_numerals **)
val rel_iff_rel_0_rls = map (inst "y" "?u+?v")
[real_less_iff_diff_less_0, real_eq_iff_diff_eq_0,
real_le_iff_diff_le_0] @
map (inst "y" "n")
[real_less_iff_diff_less_0, real_eq_iff_diff_eq_0,
real_le_iff_diff_le_0];
Goal "!!i::real. (i*u + m = j*u + n) = ((i-j)*u + m = n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]@
real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_eq_add_iff1";
Goal "!!i::real. (i*u + m = j*u + n) = (m = (j-i)*u + n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]@
real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_eq_add_iff2";
Goal "!!i::real. (i*u + m < j*u + n) = ((i-j)*u + m < n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]@
real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_less_add_iff1";
Goal "!!i::real. (i*u + m < j*u + n) = (m < (j-i)*u + n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]@
real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_less_add_iff2";
Goal "!!i::real. (i*u + m <= j*u + n) = ((i-j)*u + m <= n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]@
real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_le_add_iff1";
Goal "!!i::real. (i*u + m <= j*u + n) = (m <= (j-i)*u + n)";
by (asm_simp_tac (simpset() addsimps [real_diff_def, real_add_mult_distrib]
@real_add_ac@rel_iff_rel_0_rls) 1);
qed "real_le_add_iff2";
Addsimps [real_numeral_0_eq_0, real_numeral_1_eq_1];
structure Real_Numeral_Simprocs =
struct
(*Maps 0 to Numeral0 and 1 to Numeral1 so that arithmetic in simprocs
isn't complicated by the abstract 0 and 1.*)
val numeral_syms = [real_numeral_0_eq_0 RS sym, real_numeral_1_eq_1 RS sym];
(*Utilities*)
fun mk_numeral n = HOLogic.number_of_const HOLogic.realT $ HOLogic.mk_bin n;
(*Decodes a binary real constant, or 0, 1*)
val dest_numeral = Int_Numeral_Simprocs.dest_numeral;
val find_first_numeral = Int_Numeral_Simprocs.find_first_numeral;
val zero = mk_numeral 0;
val mk_plus = HOLogic.mk_binop "op +";
val uminus_const = Const ("uminus", HOLogic.realT --> HOLogic.realT);
(*Thus mk_sum[t] yields t+0; longer sums don't have a trailing zero*)
fun mk_sum [] = zero
| mk_sum [t,u] = mk_plus (t, u)
| mk_sum (t :: ts) = mk_plus (t, mk_sum ts);
(*this version ALWAYS includes a trailing zero*)
fun long_mk_sum [] = zero
| long_mk_sum (t :: ts) = mk_plus (t, mk_sum ts);
val dest_plus = HOLogic.dest_bin "op +" HOLogic.realT;
(*decompose additions AND subtractions as a sum*)
fun dest_summing (pos, Const ("op +", _) $ t $ u, ts) =
dest_summing (pos, t, dest_summing (pos, u, ts))
| dest_summing (pos, Const ("op -", _) $ t $ u, ts) =
dest_summing (pos, t, dest_summing (not pos, u, ts))
| dest_summing (pos, t, ts) =
if pos then t::ts else uminus_const$t :: ts;
fun dest_sum t = dest_summing (true, t, []);
val mk_diff = HOLogic.mk_binop "op -";
val dest_diff = HOLogic.dest_bin "op -" HOLogic.realT;
val one = mk_numeral 1;
val mk_times = HOLogic.mk_binop "op *";
fun mk_prod [] = one
| mk_prod [t] = t
| mk_prod (t :: ts) = if t = one then mk_prod ts
else mk_times (t, mk_prod ts);
val dest_times = HOLogic.dest_bin "op *" HOLogic.realT;
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, ts) = mk_times (mk_numeral k, ts);
(*Express t as a product of (possibly) a numeral with other sorted terms*)
fun dest_coeff sign (Const ("uminus", _) $ t) = dest_coeff (~sign) t
| dest_coeff sign t =
let val ts = sort Term.term_ord (dest_prod t)
val (n, ts') = find_first_numeral [] ts
handle TERM _ => (1, ts)
in (sign*n, mk_prod 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;
(*Simplify Numeral0+n, n+Numeral0, Numeral1*n, n*Numeral1*)
val add_0s = map rename_numerals [real_add_zero_left, real_add_zero_right];
val mult_1s = map rename_numerals [real_mult_1, real_mult_1_right] @
[real_mult_minus1, real_mult_minus1_right];
(*To perform binary arithmetic*)
val bin_simps =
[real_numeral_0_eq_0 RS sym, real_numeral_1_eq_1 RS sym,
add_real_number_of, real_add_number_of_left, minus_real_number_of,
diff_real_number_of, mult_real_number_of, real_mult_number_of_left] @
bin_arith_simps @ bin_rel_simps;
(*To evaluate binary negations of coefficients*)
val real_minus_simps = NCons_simps @
[real_minus_1_eq_m1, minus_real_number_of,
bin_minus_1, bin_minus_0, bin_minus_Pls, bin_minus_Min,
bin_pred_1, bin_pred_0, bin_pred_Pls, bin_pred_Min];
(*To let us treat subtraction as addition*)
val diff_simps = [real_diff_def, real_minus_add_distrib, real_minus_minus];
(*push the unary minus down: - x * y = x * - y
val real_minus_mult_eq_1_to_2 =
[real_minus_mult_eq1 RS sym, real_minus_mult_eq2] MRS trans |> standard;
same as real_minus_mult_commute
*)
(*to extract again any uncancelled minuses*)
val real_minus_from_mult_simps =
[real_minus_minus, real_mult_minus_eq1, real_mult_minus_eq2];
(*combine unary minus with numeric literals, however nested within a product*)
val real_mult_minus_simps =
[real_mult_assoc, real_minus_mult_eq1, real_minus_mult_commute];
(*Apply the given rewrite (if present) just once*)
fun trans_tac None = all_tac
| trans_tac (Some th) = ALLGOALS (rtac (th RS trans));
fun prove_conv name tacs sg (hyps: thm list) (t,u) =
if t aconv u then None
else
let val ct = cterm_of sg (HOLogic.mk_Trueprop (HOLogic.mk_eq (t, u)))
in Some
(prove_goalw_cterm [] ct (K tacs)
handle ERROR => error
("The error(s) above occurred while trying to prove " ^
string_of_cterm ct ^ "\nInternal failure of simproc " ^ name))
end;
(*version without the hyps argument*)
fun prove_conv_nohyps name tacs sg = prove_conv name tacs sg [];
(*Final simplification: cancel + and * *)
val simplify_meta_eq =
Int_Numeral_Simprocs.simplify_meta_eq
[real_add_zero_left, real_add_zero_right,
real_mult_0, real_mult_0_right, real_mult_1, real_mult_1_right];
fun prep_simproc (name, pats, proc) = Simplifier.mk_simproc name pats proc;
fun prep_pat s = HOLogic.read_cterm (Theory.sign_of (the_context ())) s;
val prep_pats = map prep_pat;
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 = trans_tac
val norm_tac =
ALLGOALS (simp_tac (HOL_ss addsimps add_0s@mult_1s@diff_simps@
real_minus_simps@real_add_ac))
THEN ALLGOALS (simp_tac (HOL_ss addsimps bin_simps@real_mult_minus_simps))
THEN ALLGOALS
(simp_tac (HOL_ss addsimps real_minus_from_mult_simps@
real_add_ac@real_mult_ac))
val numeral_simp_tac = ALLGOALS (simp_tac (HOL_ss addsimps add_0s@bin_simps))
val simplify_meta_eq = simplify_meta_eq
end;
structure EqCancelNumerals = CancelNumeralsFun
(open CancelNumeralsCommon
val prove_conv = prove_conv "realeq_cancel_numerals"
val mk_bal = HOLogic.mk_eq
val dest_bal = HOLogic.dest_bin "op =" HOLogic.realT
val bal_add1 = real_eq_add_iff1 RS trans
val bal_add2 = real_eq_add_iff2 RS trans
);
structure LessCancelNumerals = CancelNumeralsFun
(open CancelNumeralsCommon
val prove_conv = prove_conv "realless_cancel_numerals"
val mk_bal = HOLogic.mk_binrel "op <"
val dest_bal = HOLogic.dest_bin "op <" HOLogic.realT
val bal_add1 = real_less_add_iff1 RS trans
val bal_add2 = real_less_add_iff2 RS trans
);
structure LeCancelNumerals = CancelNumeralsFun
(open CancelNumeralsCommon
val prove_conv = prove_conv "realle_cancel_numerals"
val mk_bal = HOLogic.mk_binrel "op <="
val dest_bal = HOLogic.dest_bin "op <=" HOLogic.realT
val bal_add1 = real_le_add_iff1 RS trans
val bal_add2 = real_le_add_iff2 RS trans
);
val cancel_numerals =
map prep_simproc
[("realeq_cancel_numerals",
prep_pats ["(l::real) + m = n", "(l::real) = m + n",
"(l::real) - m = n", "(l::real) = m - n",
"(l::real) * m = n", "(l::real) = m * n"],
EqCancelNumerals.proc),
("realless_cancel_numerals",
prep_pats ["(l::real) + m < n", "(l::real) < m + n",
"(l::real) - m < n", "(l::real) < m - n",
"(l::real) * m < n", "(l::real) < m * n"],
LessCancelNumerals.proc),
("realle_cancel_numerals",
prep_pats ["(l::real) + m <= n", "(l::real) <= m + n",
"(l::real) - m <= n", "(l::real) <= m - n",
"(l::real) * m <= n", "(l::real) <= m * n"],
LeCancelNumerals.proc)];
structure CombineNumeralsData =
struct
val add = op + : int*int -> int
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 = left_real_add_mult_distrib RS trans
val prove_conv = prove_conv_nohyps "real_combine_numerals"
val trans_tac = trans_tac
val norm_tac =
ALLGOALS (simp_tac (HOL_ss addsimps numeral_syms@add_0s@mult_1s@
diff_simps@real_minus_simps@real_add_ac))
THEN ALLGOALS (simp_tac (HOL_ss addsimps bin_simps@real_mult_minus_simps))
THEN ALLGOALS (simp_tac (HOL_ss addsimps real_minus_from_mult_simps@
real_add_ac@real_mult_ac))
val numeral_simp_tac = ALLGOALS
(simp_tac (HOL_ss addsimps add_0s@bin_simps))
val simplify_meta_eq =
Int_Numeral_Simprocs.simplify_meta_eq (add_0s@mult_1s)
end;
structure CombineNumerals = CombineNumeralsFun(CombineNumeralsData);
val combine_numerals =
prep_simproc ("real_combine_numerals",
prep_pats ["(i::real) + j", "(i::real) - j"],
CombineNumerals.proc);
(** Declarations for ExtractCommonTerm **)
(*this version ALWAYS includes a trailing one*)
fun long_mk_prod [] = one
| long_mk_prod (t :: ts) = mk_times (t, mk_prod ts);
(*Find first term that matches u*)
fun find_first past u [] = raise TERM("find_first", [])
| find_first past u (t::terms) =
if u aconv t then (rev past @ terms)
else find_first (t::past) u terms
handle TERM _ => find_first (t::past) u terms;
(*Final simplification: cancel + and * *)
fun cancel_simplify_meta_eq cancel_th th =
Int_Numeral_Simprocs.simplify_meta_eq
[real_mult_1, real_mult_1_right]
(([th, cancel_th]) MRS trans);
(*** Making constant folding work for 0 and 1 too ***)
structure RealAbstractNumeralsData =
struct
val dest_eq = HOLogic.dest_eq o HOLogic.dest_Trueprop o concl_of
val is_numeral = Bin_Simprocs.is_numeral
val numeral_0_eq_0 = real_numeral_0_eq_0
val numeral_1_eq_1 = real_numeral_1_eq_1
val prove_conv = prove_conv_nohyps "real_abstract_numerals"
fun norm_tac simps = ALLGOALS (simp_tac (HOL_ss addsimps simps))
val simplify_meta_eq = Bin_Simprocs.simplify_meta_eq
end
structure RealAbstractNumerals = AbstractNumeralsFun (RealAbstractNumeralsData)
(*For addition, we already have rules for the operand 0.
Multiplication is omitted because there are already special rules for
both 0 and 1 as operands. Unary minus is trivial, just have - 1 = -1.
For the others, having three patterns is a compromise between just having
one (many spurious calls) and having nine (just too many!) *)
val eval_numerals =
map prep_simproc
[("real_add_eval_numerals",
prep_pats ["(m::real) + 1", "(m::real) + number_of v"],
RealAbstractNumerals.proc add_real_number_of),
("real_diff_eval_numerals",
prep_pats ["(m::real) - 1", "(m::real) - number_of v"],
RealAbstractNumerals.proc diff_real_number_of),
("real_eq_eval_numerals",
prep_pats ["(m::real) = 0", "(m::real) = 1", "(m::real) = number_of v"],
RealAbstractNumerals.proc eq_real_number_of),
("real_less_eval_numerals",
prep_pats ["(m::real) < 0", "(m::real) < 1", "(m::real) < number_of v"],
RealAbstractNumerals.proc less_real_number_of),
("real_le_eval_numerals",
prep_pats ["(m::real) <= 0", "(m::real) <= 1", "(m::real) <= number_of v"],
RealAbstractNumerals.proc le_real_number_of_eq_not_less)]
end;
Addsimprocs Real_Numeral_Simprocs.eval_numerals;
Addsimprocs Real_Numeral_Simprocs.cancel_numerals;
Addsimprocs [Real_Numeral_Simprocs.combine_numerals];
(*The Abel_Cancel simprocs are now obsolete*)
Delsimprocs [Real_Cancel.sum_conv, Real_Cancel.rel_conv];
(*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::real)";
test "2*u = (u::real)";
test "(i + j + 12 + (k::real)) - 15 = y";
test "(i + j + 12 + (k::real)) - 5 = y";
test "y - b < (b::real)";
test "y - (3*b + c) < (b::real) - 2*c";
test "(2*x - (u*v) + y) - v*3*u = (w::real)";
test "(2*x*u*v + (u*v)*4 + y) - v*u*4 = (w::real)";
test "(2*x*u*v + (u*v)*4 + y) - v*u = (w::real)";
test "u*v - (x*u*v + (u*v)*4 + y) = (w::real)";
test "(i + j + 12 + (k::real)) = u + 15 + y";
test "(i + j*2 + 12 + (k::real)) = 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::real)";
test "a + -(b+c) + b = (d::real)";
test "a + -(b+c) - b = (d::real)";
(*negative numerals*)
test "(i + j + -2 + (k::real)) - (u + 5 + y) = zz";
test "(i + j + -3 + (k::real)) < u + 5 + y";
test "(i + j + 3 + (k::real)) < u + -6 + y";
test "(i + j + -12 + (k::real)) - 15 = y";
test "(i + j + 12 + (k::real)) - -15 = y";
test "(i + j + -12 + (k::real)) - -15 = y";
*)
(** Constant folding for real plus and times **)
(*We do not need
structure Real_Plus_Assoc = Assoc_Fold (Real_Plus_Assoc_Data);
because combine_numerals does the same thing*)
structure Real_Times_Assoc_Data : ASSOC_FOLD_DATA =
struct
val ss = HOL_ss
val eq_reflection = eq_reflection
val sg_ref = Sign.self_ref (Theory.sign_of (the_context ()))
val T = HOLogic.realT
val plus = Const ("op *", [HOLogic.realT,HOLogic.realT] ---> HOLogic.realT)
val add_ac = real_mult_ac
end;
structure Real_Times_Assoc = Assoc_Fold (Real_Times_Assoc_Data);
Addsimprocs [Real_Times_Assoc.conv];
(*Simplification of x-y < 0, etc.*)
AddIffs [real_less_iff_diff_less_0 RS sym];
AddIffs [real_eq_iff_diff_eq_0 RS sym];
AddIffs [real_le_iff_diff_le_0 RS sym];
(** <= monotonicity results: needed for arithmetic **)
Goal "[| i <= j; (0::real) <= k |] ==> i*k <= j*k";
by (auto_tac (claset(),
simpset() addsimps [order_le_less, real_mult_less_mono1]));
qed "real_mult_le_mono1";
Goal "[| i <= j; (0::real) <= k |] ==> k*i <= k*j";
by (dtac real_mult_le_mono1 1);
by (ALLGOALS (asm_full_simp_tac (simpset() addsimps [real_mult_commute])));
qed "real_mult_le_mono2";
Goal "[| (i::real) <= j; k <= l; 0 <= j; 0 <= k |] ==> i*k <= j*l";
by (etac (real_mult_le_mono1 RS order_trans) 1);
by (assume_tac 1);
by (etac real_mult_le_mono2 1);
by (assume_tac 1);
qed "real_mult_le_mono";
Addsimps [real_minus_1_eq_m1];