src/HOL/Tools/int_arith.ML
author haftmann
Wed Dec 03 15:58:44 2008 +0100 (2008-12-03)
changeset 28952 15a4b2cf8c34
parent 28262 src/HOL/int_arith1.ML@aa7ca36d67fd
child 29269 5c25a2012975
permissions -rw-r--r--
made repository layout more coherent with logical distribution structure; stripped some $Id$s
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(*  Title:      HOL/int_arith1.ML
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    ID:         $Id$
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    Authors:    Larry Paulson and Tobias Nipkow
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Simprocs and decision procedure for linear arithmetic.
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*)
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structure Int_Numeral_Base_Simprocs =
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  struct
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  fun prove_conv tacs ctxt (_: thm list) (t, u) =
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    if t aconv u then NONE
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    else
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      let val eq = HOLogic.mk_Trueprop (HOLogic.mk_eq (t, u))
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      in SOME (Goal.prove ctxt [] [] eq (K (EVERY tacs))) end
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  fun prove_conv_nohyps tacs sg = prove_conv tacs sg [];
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  fun prep_simproc (name, pats, proc) =
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    Simplifier.simproc (the_context()) name pats proc;
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  fun is_numeral (Const(@{const_name Int.number_of}, _) $ w) = true
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    | is_numeral _ = false
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  fun simplify_meta_eq f_number_of_eq f_eq =
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      mk_meta_eq ([f_eq, f_number_of_eq] MRS trans)
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  (*reorientation simprules using ==, for the following simproc*)
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  val meta_zero_reorient = @{thm zero_reorient} RS eq_reflection
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  val meta_one_reorient = @{thm one_reorient} RS eq_reflection
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  val meta_number_of_reorient = @{thm number_of_reorient} RS eq_reflection
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  (*reorientation simplification procedure: reorients (polymorphic) 
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    0 = x, 1 = x, nnn = x provided x isn't 0, 1 or a Int.*)
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  fun reorient_proc sg _ (_ $ t $ u) =
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    case u of
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        Const(@{const_name HOL.zero}, _) => NONE
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      | Const(@{const_name HOL.one}, _) => NONE
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      | Const(@{const_name Int.number_of}, _) $ _ => NONE
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      | _ => SOME (case t of
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          Const(@{const_name HOL.zero}, _) => meta_zero_reorient
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        | Const(@{const_name HOL.one}, _) => meta_one_reorient
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        | Const(@{const_name Int.number_of}, _) $ _ => meta_number_of_reorient)
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  val reorient_simproc = 
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      prep_simproc ("reorient_simproc", ["0=x", "1=x", "number_of w = x"], reorient_proc)
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  end;
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Addsimprocs [Int_Numeral_Base_Simprocs.reorient_simproc];
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structure Int_Numeral_Simprocs =
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struct
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(*Maps 0 to Numeral0 and 1 to Numeral1 so that arithmetic in Int_Numeral_Base_Simprocs
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  isn't complicated by the abstract 0 and 1.*)
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val numeral_syms = [@{thm numeral_0_eq_0} RS sym, @{thm numeral_1_eq_1} RS sym];
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(** New term ordering so that AC-rewriting brings numerals to the front **)
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(*Order integers by absolute value and then by sign. The standard integer
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  ordering is not well-founded.*)
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fun num_ord (i,j) =
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  (case int_ord (abs i, abs j) of
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    EQUAL => int_ord (Int.sign i, Int.sign j) 
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  | ord => ord);
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(*This resembles Term.term_ord, but it puts binary numerals before other
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  non-atomic terms.*)
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local open Term 
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in 
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fun numterm_ord (Abs (_, T, t), Abs(_, U, u)) =
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      (case numterm_ord (t, u) of EQUAL => typ_ord (T, U) | ord => ord)
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  | numterm_ord
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     (Const(@{const_name Int.number_of}, _) $ v, Const(@{const_name Int.number_of}, _) $ w) =
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     num_ord (HOLogic.dest_numeral v, HOLogic.dest_numeral w)
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  | numterm_ord (Const(@{const_name Int.number_of}, _) $ _, _) = LESS
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  | numterm_ord (_, Const(@{const_name Int.number_of}, _) $ _) = GREATER
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  | numterm_ord (t, u) =
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      (case int_ord (size_of_term t, size_of_term u) of
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        EQUAL =>
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          let val (f, ts) = strip_comb t and (g, us) = strip_comb u in
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            (case hd_ord (f, g) of EQUAL => numterms_ord (ts, us) | ord => ord)
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          end
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      | ord => ord)
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and numterms_ord (ts, us) = list_ord numterm_ord (ts, us)
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end;
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fun numtermless tu = (numterm_ord tu = LESS);
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(*Defined in this file, but perhaps needed only for Int_Numeral_Base_Simprocs of type nat.*)
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val num_ss = HOL_ss settermless numtermless;
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(** Utilities **)
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fun mk_number T n = HOLogic.number_of_const T $ HOLogic.mk_numeral n;
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fun find_first_numeral past (t::terms) =
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        ((snd (HOLogic.dest_number t), rev past @ terms)
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         handle TERM _ => find_first_numeral (t::past) terms)
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  | find_first_numeral past [] = raise TERM("find_first_numeral", []);
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val mk_plus = HOLogic.mk_binop @{const_name HOL.plus};
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fun mk_minus t = 
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  let val T = Term.fastype_of t
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  in Const (@{const_name HOL.uminus}, T --> T) $ t end;
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(*Thus mk_sum[t] yields t+0; longer sums don't have a trailing zero*)
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fun mk_sum T []        = mk_number T 0
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  | mk_sum T [t,u]     = mk_plus (t, u)
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  | mk_sum T (t :: ts) = mk_plus (t, mk_sum T ts);
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(*this version ALWAYS includes a trailing zero*)
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fun long_mk_sum T []        = mk_number T 0
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  | long_mk_sum T (t :: ts) = mk_plus (t, mk_sum T ts);
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val dest_plus = HOLogic.dest_bin @{const_name HOL.plus} Term.dummyT;
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(*decompose additions AND subtractions as a sum*)
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fun dest_summing (pos, Const (@{const_name HOL.plus}, _) $ t $ u, ts) =
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        dest_summing (pos, t, dest_summing (pos, u, ts))
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  | dest_summing (pos, Const (@{const_name HOL.minus}, _) $ t $ u, ts) =
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        dest_summing (pos, t, dest_summing (not pos, u, ts))
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  | dest_summing (pos, t, ts) =
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        if pos then t::ts else mk_minus t :: ts;
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fun dest_sum t = dest_summing (true, t, []);
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val mk_diff = HOLogic.mk_binop @{const_name HOL.minus};
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val dest_diff = HOLogic.dest_bin @{const_name HOL.minus} Term.dummyT;
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val mk_times = HOLogic.mk_binop @{const_name HOL.times};
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fun one_of T = Const(@{const_name HOL.one},T);
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(* build product with trailing 1 rather than Numeral 1 in order to avoid the
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   unnecessary restriction to type class number_ring
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   which is not required for cancellation of common factors in divisions.
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*)
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fun mk_prod T = 
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  let val one = one_of T
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  fun mk [] = one
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    | mk [t] = t
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    | mk (t :: ts) = if t = one then mk ts else mk_times (t, mk ts)
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  in mk end;
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(*This version ALWAYS includes a trailing one*)
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fun long_mk_prod T []        = one_of T
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  | long_mk_prod T (t :: ts) = mk_times (t, mk_prod T ts);
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val dest_times = HOLogic.dest_bin @{const_name HOL.times} Term.dummyT;
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fun dest_prod t =
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      let val (t,u) = dest_times t
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      in dest_prod t @ dest_prod u end
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      handle TERM _ => [t];
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(*DON'T do the obvious simplifications; that would create special cases*)
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fun mk_coeff (k, t) = mk_times (mk_number (Term.fastype_of t) k, t);
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(*Express t as a product of (possibly) a numeral with other sorted terms*)
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fun dest_coeff sign (Const (@{const_name HOL.uminus}, _) $ t) = dest_coeff (~sign) t
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  | dest_coeff sign t =
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    let val ts = sort Term.term_ord (dest_prod t)
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        val (n, ts') = find_first_numeral [] ts
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                          handle TERM _ => (1, ts)
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    in (sign*n, mk_prod (Term.fastype_of t) ts') end;
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(*Find first coefficient-term THAT MATCHES u*)
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fun find_first_coeff past u [] = raise TERM("find_first_coeff", [])
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  | find_first_coeff past u (t::terms) =
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        let val (n,u') = dest_coeff 1 t
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        in if u aconv u' then (n, rev past @ terms)
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                         else find_first_coeff (t::past) u terms
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        end
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        handle TERM _ => find_first_coeff (t::past) u terms;
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(*Fractions as pairs of ints. Can't use Rat.rat because the representation
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  needs to preserve negative values in the denominator.*)
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fun mk_frac (p, q) = if q = 0 then raise Div else (p, q);
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(*Don't reduce fractions; sums must be proved by rule add_frac_eq.
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  Fractions are reduced later by the cancel_numeral_factor simproc.*)
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fun add_frac ((p1, q1), (p2, q2)) = (p1 * q2 + p2 * q1, q1 * q2);
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val mk_divide = HOLogic.mk_binop @{const_name HOL.divide};
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(*Build term (p / q) * t*)
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fun mk_fcoeff ((p, q), t) =
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  let val T = Term.fastype_of t
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  in mk_times (mk_divide (mk_number T p, mk_number T q), t) end;
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(*Express t as a product of a fraction with other sorted terms*)
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fun dest_fcoeff sign (Const (@{const_name HOL.uminus}, _) $ t) = dest_fcoeff (~sign) t
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  | dest_fcoeff sign (Const (@{const_name HOL.divide}, _) $ t $ u) =
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    let val (p, t') = dest_coeff sign t
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        val (q, u') = dest_coeff 1 u
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    in (mk_frac (p, q), mk_divide (t', u')) end
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  | dest_fcoeff sign t =
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    let val (p, t') = dest_coeff sign t
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        val T = Term.fastype_of t
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    in (mk_frac (p, 1), mk_divide (t', one_of T)) end;
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(*Simplify Numeral0+n, n+Numeral0, Numeral1*n, n*Numeral1, 1*x, x*1, x/1 *)
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val add_0s =  thms "add_0s";
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val mult_1s = thms "mult_1s" @ [thm"mult_1_left", thm"mult_1_right", thm"divide_1"];
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(*Simplify inverse Numeral1, a/Numeral1*)
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val inverse_1s = [@{thm inverse_numeral_1}];
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val divide_1s = [@{thm divide_numeral_1}];
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(*To perform binary arithmetic.  The "left" rewriting handles patterns
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  created by the Int_Numeral_Base_Simprocs, such as 3 * (5 * x). *)
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val simps = [@{thm numeral_0_eq_0} RS sym, @{thm numeral_1_eq_1} RS sym,
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                 @{thm add_number_of_left}, @{thm mult_number_of_left}] @
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                @{thms arith_simps} @ @{thms rel_simps};
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(*Binary arithmetic BUT NOT ADDITION since it may collapse adjacent terms
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  during re-arrangement*)
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val non_add_simps =
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  subtract Thm.eq_thm [@{thm add_number_of_left}, @{thm number_of_add} RS sym] simps;
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(*To evaluate binary negations of coefficients*)
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val minus_simps = [@{thm numeral_m1_eq_minus_1} RS sym, @{thm number_of_minus} RS sym] @
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                   @{thms minus_bin_simps} @ @{thms pred_bin_simps};
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(*To let us treat subtraction as addition*)
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val diff_simps = [@{thm diff_minus}, @{thm minus_add_distrib}, @{thm minus_minus}];
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(*To let us treat division as multiplication*)
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val divide_simps = [@{thm divide_inverse}, @{thm inverse_mult_distrib}, @{thm inverse_inverse_eq}];
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(*push the unary minus down: - x * y = x * - y *)
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val minus_mult_eq_1_to_2 =
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    [@{thm minus_mult_left} RS sym, @{thm minus_mult_right}] MRS trans |> standard;
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(*to extract again any uncancelled minuses*)
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val minus_from_mult_simps =
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    [@{thm minus_minus}, @{thm minus_mult_left} RS sym, @{thm minus_mult_right} RS sym];
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(*combine unary minus with numeric literals, however nested within a product*)
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val mult_minus_simps =
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    [@{thm mult_assoc}, @{thm minus_mult_left}, minus_mult_eq_1_to_2];
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(*Apply the given rewrite (if present) just once*)
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fun trans_tac NONE      = all_tac
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  | trans_tac (SOME th) = ALLGOALS (rtac (th RS trans));
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fun simplify_meta_eq rules =
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  let val ss0 = HOL_basic_ss addeqcongs [eq_cong2] addsimps rules
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  in fn ss => simplify (Simplifier.inherit_context ss ss0) o mk_meta_eq end
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structure CancelNumeralsCommon =
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  struct
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  val mk_sum            = mk_sum
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  val dest_sum          = dest_sum
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  val mk_coeff          = mk_coeff
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  val dest_coeff        = dest_coeff 1
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  val find_first_coeff  = find_first_coeff []
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  val trans_tac         = fn _ => trans_tac
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  val norm_ss1 = num_ss addsimps numeral_syms @ add_0s @ mult_1s @
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    diff_simps @ minus_simps @ @{thms add_ac}
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  val norm_ss2 = num_ss addsimps non_add_simps @ mult_minus_simps
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  val norm_ss3 = num_ss addsimps minus_from_mult_simps @ @{thms add_ac} @ @{thms mult_ac}
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  fun norm_tac ss =
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    ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1))
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    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
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    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
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  val numeral_simp_ss = HOL_ss addsimps add_0s @ simps
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  fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
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  val simplify_meta_eq = simplify_meta_eq (add_0s @ mult_1s)
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  end;
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structure EqCancelNumerals = CancelNumeralsFun
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 (open CancelNumeralsCommon
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  val prove_conv = Int_Numeral_Base_Simprocs.prove_conv
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  val mk_bal   = HOLogic.mk_eq
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  val dest_bal = HOLogic.dest_bin "op =" Term.dummyT
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  val bal_add1 = @{thm eq_add_iff1} RS trans
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  val bal_add2 = @{thm eq_add_iff2} RS trans
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);
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structure LessCancelNumerals = CancelNumeralsFun
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 (open CancelNumeralsCommon
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  val prove_conv = Int_Numeral_Base_Simprocs.prove_conv
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  val mk_bal   = HOLogic.mk_binrel @{const_name HOL.less}
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  val dest_bal = HOLogic.dest_bin @{const_name HOL.less} Term.dummyT
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  val bal_add1 = @{thm less_add_iff1} RS trans
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  val bal_add2 = @{thm less_add_iff2} RS trans
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   297
);
wenzelm@23164
   298
wenzelm@23164
   299
structure LeCancelNumerals = CancelNumeralsFun
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   300
 (open CancelNumeralsCommon
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   301
  val prove_conv = Int_Numeral_Base_Simprocs.prove_conv
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   302
  val mk_bal   = HOLogic.mk_binrel @{const_name HOL.less_eq}
haftmann@23881
   303
  val dest_bal = HOLogic.dest_bin @{const_name HOL.less_eq} Term.dummyT
haftmann@25481
   304
  val bal_add1 = @{thm le_add_iff1} RS trans
haftmann@25481
   305
  val bal_add2 = @{thm le_add_iff2} RS trans
wenzelm@23164
   306
);
wenzelm@23164
   307
wenzelm@23164
   308
val cancel_numerals =
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   309
  map Int_Numeral_Base_Simprocs.prep_simproc
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   310
   [("inteq_cancel_numerals",
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   311
     ["(l::'a::number_ring) + m = n",
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   312
      "(l::'a::number_ring) = m + n",
wenzelm@23164
   313
      "(l::'a::number_ring) - m = n",
wenzelm@23164
   314
      "(l::'a::number_ring) = m - n",
wenzelm@23164
   315
      "(l::'a::number_ring) * m = n",
wenzelm@23164
   316
      "(l::'a::number_ring) = m * n"],
wenzelm@23164
   317
     K EqCancelNumerals.proc),
wenzelm@23164
   318
    ("intless_cancel_numerals",
wenzelm@23164
   319
     ["(l::'a::{ordered_idom,number_ring}) + m < n",
wenzelm@23164
   320
      "(l::'a::{ordered_idom,number_ring}) < m + n",
wenzelm@23164
   321
      "(l::'a::{ordered_idom,number_ring}) - m < n",
wenzelm@23164
   322
      "(l::'a::{ordered_idom,number_ring}) < m - n",
wenzelm@23164
   323
      "(l::'a::{ordered_idom,number_ring}) * m < n",
wenzelm@23164
   324
      "(l::'a::{ordered_idom,number_ring}) < m * n"],
wenzelm@23164
   325
     K LessCancelNumerals.proc),
wenzelm@23164
   326
    ("intle_cancel_numerals",
wenzelm@23164
   327
     ["(l::'a::{ordered_idom,number_ring}) + m <= n",
wenzelm@23164
   328
      "(l::'a::{ordered_idom,number_ring}) <= m + n",
wenzelm@23164
   329
      "(l::'a::{ordered_idom,number_ring}) - m <= n",
wenzelm@23164
   330
      "(l::'a::{ordered_idom,number_ring}) <= m - n",
wenzelm@23164
   331
      "(l::'a::{ordered_idom,number_ring}) * m <= n",
wenzelm@23164
   332
      "(l::'a::{ordered_idom,number_ring}) <= m * n"],
wenzelm@23164
   333
     K LeCancelNumerals.proc)];
wenzelm@23164
   334
wenzelm@23164
   335
wenzelm@23164
   336
structure CombineNumeralsData =
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   337
  struct
wenzelm@24630
   338
  type coeff            = int
wenzelm@24630
   339
  val iszero            = (fn x => x = 0)
wenzelm@24630
   340
  val add               = op +
wenzelm@23164
   341
  val mk_sum            = long_mk_sum    (*to work for e.g. 2*x + 3*x *)
wenzelm@23164
   342
  val dest_sum          = dest_sum
wenzelm@23164
   343
  val mk_coeff          = mk_coeff
wenzelm@23164
   344
  val dest_coeff        = dest_coeff 1
haftmann@25481
   345
  val left_distrib      = @{thm combine_common_factor} RS trans
wenzelm@23164
   346
  val prove_conv        = Int_Numeral_Base_Simprocs.prove_conv_nohyps
wenzelm@23164
   347
  val trans_tac         = fn _ => trans_tac
wenzelm@23164
   348
wenzelm@23164
   349
  val norm_ss1 = num_ss addsimps numeral_syms @ add_0s @ mult_1s @
haftmann@23881
   350
    diff_simps @ minus_simps @ @{thms add_ac}
wenzelm@23164
   351
  val norm_ss2 = num_ss addsimps non_add_simps @ mult_minus_simps
haftmann@23881
   352
  val norm_ss3 = num_ss addsimps minus_from_mult_simps @ @{thms add_ac} @ @{thms mult_ac}
wenzelm@23164
   353
  fun norm_tac ss =
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   354
    ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1))
wenzelm@23164
   355
    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
wenzelm@23164
   356
    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
wenzelm@23164
   357
wenzelm@23164
   358
  val numeral_simp_ss = HOL_ss addsimps add_0s @ simps
wenzelm@23164
   359
  fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
wenzelm@23164
   360
  val simplify_meta_eq = simplify_meta_eq (add_0s @ mult_1s)
wenzelm@23164
   361
  end;
wenzelm@23164
   362
wenzelm@23164
   363
structure CombineNumerals = CombineNumeralsFun(CombineNumeralsData);
wenzelm@23164
   364
wenzelm@23164
   365
(*Version for fields, where coefficients can be fractions*)
wenzelm@23164
   366
structure FieldCombineNumeralsData =
wenzelm@23164
   367
  struct
wenzelm@24630
   368
  type coeff            = int * int
wenzelm@24630
   369
  val iszero            = (fn (p, q) => p = 0)
wenzelm@23164
   370
  val add               = add_frac
wenzelm@23164
   371
  val mk_sum            = long_mk_sum
wenzelm@23164
   372
  val dest_sum          = dest_sum
wenzelm@23164
   373
  val mk_coeff          = mk_fcoeff
wenzelm@23164
   374
  val dest_coeff        = dest_fcoeff 1
haftmann@25481
   375
  val left_distrib      = @{thm combine_common_factor} RS trans
wenzelm@23164
   376
  val prove_conv        = Int_Numeral_Base_Simprocs.prove_conv_nohyps
wenzelm@23164
   377
  val trans_tac         = fn _ => trans_tac
wenzelm@23164
   378
wenzelm@23164
   379
  val norm_ss1 = num_ss addsimps numeral_syms @ add_0s @ mult_1s @
haftmann@23881
   380
    inverse_1s @ divide_simps @ diff_simps @ minus_simps @ @{thms add_ac}
wenzelm@23164
   381
  val norm_ss2 = num_ss addsimps non_add_simps @ mult_minus_simps
haftmann@23881
   382
  val norm_ss3 = num_ss addsimps minus_from_mult_simps @ @{thms add_ac} @ @{thms mult_ac}
wenzelm@23164
   383
  fun norm_tac ss =
wenzelm@23164
   384
    ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss1))
wenzelm@23164
   385
    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss2))
wenzelm@23164
   386
    THEN ALLGOALS (simp_tac (Simplifier.inherit_context ss norm_ss3))
wenzelm@23164
   387
wenzelm@23164
   388
  val numeral_simp_ss = HOL_ss addsimps add_0s @ simps @ [@{thm add_frac_eq}]
wenzelm@23164
   389
  fun numeral_simp_tac ss = ALLGOALS (simp_tac (Simplifier.inherit_context ss numeral_simp_ss))
wenzelm@23164
   390
  val simplify_meta_eq = simplify_meta_eq (add_0s @ mult_1s @ divide_1s)
wenzelm@23164
   391
  end;
wenzelm@23164
   392
wenzelm@23164
   393
structure FieldCombineNumerals = CombineNumeralsFun(FieldCombineNumeralsData);
wenzelm@23164
   394
wenzelm@23164
   395
val combine_numerals =
wenzelm@23164
   396
  Int_Numeral_Base_Simprocs.prep_simproc
wenzelm@23164
   397
    ("int_combine_numerals", 
wenzelm@23164
   398
     ["(i::'a::number_ring) + j", "(i::'a::number_ring) - j"], 
wenzelm@23164
   399
     K CombineNumerals.proc);
wenzelm@23164
   400
wenzelm@23164
   401
val field_combine_numerals =
wenzelm@23164
   402
  Int_Numeral_Base_Simprocs.prep_simproc
wenzelm@23164
   403
    ("field_combine_numerals", 
wenzelm@23164
   404
     ["(i::'a::{number_ring,field,division_by_zero}) + j",
wenzelm@23164
   405
      "(i::'a::{number_ring,field,division_by_zero}) - j"], 
wenzelm@23164
   406
     K FieldCombineNumerals.proc);
wenzelm@23164
   407
wenzelm@23164
   408
end;
wenzelm@23164
   409
wenzelm@23164
   410
Addsimprocs Int_Numeral_Simprocs.cancel_numerals;
wenzelm@23164
   411
Addsimprocs [Int_Numeral_Simprocs.combine_numerals];
wenzelm@23164
   412
Addsimprocs [Int_Numeral_Simprocs.field_combine_numerals];
wenzelm@23164
   413
wenzelm@23164
   414
(*examples:
wenzelm@23164
   415
print_depth 22;
wenzelm@23164
   416
set timing;
wenzelm@23164
   417
set trace_simp;
wenzelm@23164
   418
fun test s = (Goal s, by (Simp_tac 1));
wenzelm@23164
   419
wenzelm@23164
   420
test "l + 2 + 2 + 2 + (l + 2) + (oo + 2) = (uu::int)";
wenzelm@23164
   421
wenzelm@23164
   422
test "2*u = (u::int)";
wenzelm@23164
   423
test "(i + j + 12 + (k::int)) - 15 = y";
wenzelm@23164
   424
test "(i + j + 12 + (k::int)) - 5 = y";
wenzelm@23164
   425
wenzelm@23164
   426
test "y - b < (b::int)";
wenzelm@23164
   427
test "y - (3*b + c) < (b::int) - 2*c";
wenzelm@23164
   428
wenzelm@23164
   429
test "(2*x - (u*v) + y) - v*3*u = (w::int)";
wenzelm@23164
   430
test "(2*x*u*v + (u*v)*4 + y) - v*u*4 = (w::int)";
wenzelm@23164
   431
test "(2*x*u*v + (u*v)*4 + y) - v*u = (w::int)";
wenzelm@23164
   432
test "u*v - (x*u*v + (u*v)*4 + y) = (w::int)";
wenzelm@23164
   433
wenzelm@23164
   434
test "(i + j + 12 + (k::int)) = u + 15 + y";
wenzelm@23164
   435
test "(i + j*2 + 12 + (k::int)) = j + 5 + y";
wenzelm@23164
   436
wenzelm@23164
   437
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)";
wenzelm@23164
   438
wenzelm@23164
   439
test "a + -(b+c) + b = (d::int)";
wenzelm@23164
   440
test "a + -(b+c) - b = (d::int)";
wenzelm@23164
   441
wenzelm@23164
   442
(*negative numerals*)
wenzelm@23164
   443
test "(i + j + -2 + (k::int)) - (u + 5 + y) = zz";
wenzelm@23164
   444
test "(i + j + -3 + (k::int)) < u + 5 + y";
wenzelm@23164
   445
test "(i + j + 3 + (k::int)) < u + -6 + y";
wenzelm@23164
   446
test "(i + j + -12 + (k::int)) - 15 = y";
wenzelm@23164
   447
test "(i + j + 12 + (k::int)) - -15 = y";
wenzelm@23164
   448
test "(i + j + -12 + (k::int)) - -15 = y";
wenzelm@23164
   449
*)
wenzelm@23164
   450
wenzelm@23164
   451
wenzelm@23164
   452
(** Constant folding for multiplication in semirings **)
wenzelm@23164
   453
wenzelm@23164
   454
(*We do not need folding for addition: combine_numerals does the same thing*)
wenzelm@23164
   455
wenzelm@23164
   456
structure Semiring_Times_Assoc_Data : ASSOC_FOLD_DATA =
wenzelm@23164
   457
struct
haftmann@23881
   458
  val assoc_ss = HOL_ss addsimps @{thms mult_ac}
wenzelm@23164
   459
  val eq_reflection = eq_reflection
wenzelm@23164
   460
end;
wenzelm@23164
   461
wenzelm@23164
   462
structure Semiring_Times_Assoc = Assoc_Fold (Semiring_Times_Assoc_Data);
wenzelm@23164
   463
wenzelm@23164
   464
val assoc_fold_simproc =
wenzelm@23164
   465
  Int_Numeral_Base_Simprocs.prep_simproc
wenzelm@23164
   466
   ("semiring_assoc_fold", ["(a::'a::comm_semiring_1_cancel) * b"],
wenzelm@23164
   467
    K Semiring_Times_Assoc.proc);
wenzelm@23164
   468
wenzelm@23164
   469
Addsimprocs [assoc_fold_simproc];
wenzelm@23164
   470
wenzelm@23164
   471
wenzelm@23164
   472
wenzelm@23164
   473
wenzelm@23164
   474
(*** decision procedure for linear arithmetic ***)
wenzelm@23164
   475
wenzelm@23164
   476
(*---------------------------------------------------------------------------*)
wenzelm@23164
   477
(* Linear arithmetic                                                         *)
wenzelm@23164
   478
(*---------------------------------------------------------------------------*)
wenzelm@23164
   479
wenzelm@23164
   480
(*
wenzelm@23164
   481
Instantiation of the generic linear arithmetic package for int.
wenzelm@23164
   482
*)
wenzelm@23164
   483
wenzelm@23164
   484
(* Update parameters of arithmetic prover *)
wenzelm@23164
   485
local
wenzelm@23164
   486
nipkow@24266
   487
(* reduce contradictory =/</<= to False *)
nipkow@24266
   488
nipkow@24266
   489
(* Evaluation of terms of the form "m R n" where R is one of "=", "<=" or "<",
nipkow@24266
   490
   and m and n are ground terms over rings (roughly speaking).
nipkow@24266
   491
   That is, m and n consist only of 1s combined with "+", "-" and "*".
nipkow@24266
   492
*)
nipkow@24266
   493
local
nipkow@24266
   494
val zeroth = (symmetric o mk_meta_eq) @{thm of_int_0};
nipkow@24266
   495
val lhss0 = [@{cpat "0::?'a::ring"}];
nipkow@24266
   496
fun proc0 phi ss ct =
nipkow@24266
   497
  let val T = ctyp_of_term ct
nipkow@24266
   498
  in if typ_of T = @{typ int} then NONE else
nipkow@24266
   499
     SOME (instantiate' [SOME T] [] zeroth)
nipkow@24266
   500
  end;
nipkow@24266
   501
val zero_to_of_int_zero_simproc =
nipkow@24266
   502
  make_simproc {lhss = lhss0, name = "zero_to_of_int_zero_simproc",
nipkow@24266
   503
  proc = proc0, identifier = []};
nipkow@24266
   504
nipkow@24266
   505
val oneth = (symmetric o mk_meta_eq) @{thm of_int_1};
nipkow@24266
   506
val lhss1 = [@{cpat "1::?'a::ring_1"}];
nipkow@24266
   507
fun proc1 phi ss ct =
nipkow@24266
   508
  let val T = ctyp_of_term ct
nipkow@24266
   509
  in if typ_of T = @{typ int} then NONE else
nipkow@24266
   510
     SOME (instantiate' [SOME T] [] oneth)
nipkow@24266
   511
  end;
nipkow@24266
   512
val one_to_of_int_one_simproc =
nipkow@24266
   513
  make_simproc {lhss = lhss1, name = "one_to_of_int_one_simproc",
nipkow@24266
   514
  proc = proc1, identifier = []};
nipkow@24266
   515
nipkow@24266
   516
val allowed_consts =
nipkow@24266
   517
  [@{const_name "op ="}, @{const_name "HOL.times"}, @{const_name "HOL.uminus"},
nipkow@24266
   518
   @{const_name "HOL.minus"}, @{const_name "HOL.plus"},
nipkow@24266
   519
   @{const_name "HOL.zero"}, @{const_name "HOL.one"}, @{const_name "HOL.less"},
nipkow@24266
   520
   @{const_name "HOL.less_eq"}];
nipkow@24266
   521
nipkow@24266
   522
fun check t = case t of
nipkow@24266
   523
   Const(s,t) => if s = @{const_name "HOL.one"} then not (t = @{typ int})
nipkow@24266
   524
                else s mem_string allowed_consts
nipkow@24266
   525
 | a$b => check a andalso check b
nipkow@24266
   526
 | _ => false;
nipkow@24266
   527
nipkow@24266
   528
val conv =
nipkow@24266
   529
  Simplifier.rewrite
nipkow@24266
   530
   (HOL_basic_ss addsimps
nipkow@24266
   531
     ((map (fn th => th RS sym) [@{thm of_int_add}, @{thm of_int_mult},
nipkow@24266
   532
             @{thm of_int_diff},  @{thm of_int_minus}])@
nipkow@24266
   533
      [@{thm of_int_less_iff}, @{thm of_int_le_iff}, @{thm of_int_eq_iff}])
nipkow@24266
   534
     addsimprocs [zero_to_of_int_zero_simproc,one_to_of_int_one_simproc]);
nipkow@24266
   535
nipkow@24266
   536
fun sproc phi ss ct = if check (term_of ct) then SOME (conv ct) else NONE
nipkow@24266
   537
val lhss' =
nipkow@24266
   538
  [@{cpat "(?x::?'a::ring_char_0) = (?y::?'a)"},
nipkow@24266
   539
   @{cpat "(?x::?'a::ordered_idom) < (?y::?'a)"},
nipkow@24266
   540
   @{cpat "(?x::?'a::ordered_idom) <= (?y::?'a)"}]
nipkow@24266
   541
in
nipkow@24266
   542
val zero_one_idom_simproc =
nipkow@24266
   543
  make_simproc {lhss = lhss' , name = "zero_one_idom_simproc",
nipkow@24266
   544
  proc = sproc, identifier = []}
nipkow@24266
   545
end;
nipkow@24266
   546
wenzelm@23164
   547
val add_rules =
haftmann@25481
   548
    simp_thms @ @{thms arith_simps} @ @{thms rel_simps} @ @{thms arith_special} @
wenzelm@23164
   549
    [@{thm neg_le_iff_le}, @{thm numeral_0_eq_0}, @{thm numeral_1_eq_1},
wenzelm@23164
   550
     @{thm minus_zero}, @{thm diff_minus}, @{thm left_minus}, @{thm right_minus},
huffman@26086
   551
     @{thm mult_zero_left}, @{thm mult_zero_right}, @{thm mult_Bit1}, @{thm mult_1_right},
wenzelm@23164
   552
     @{thm minus_mult_left} RS sym, @{thm minus_mult_right} RS sym,
wenzelm@23164
   553
     @{thm minus_add_distrib}, @{thm minus_minus}, @{thm mult_assoc},
huffman@23365
   554
     @{thm of_nat_0}, @{thm of_nat_1}, @{thm of_nat_Suc}, @{thm of_nat_add},
huffman@23365
   555
     @{thm of_nat_mult}, @{thm of_int_0}, @{thm of_int_1}, @{thm of_int_add},
huffman@23365
   556
     @{thm of_int_mult}]
wenzelm@23164
   557
huffman@23365
   558
val nat_inj_thms = [@{thm zle_int} RS iffD2, @{thm int_int_eq} RS iffD2]
wenzelm@23164
   559
nipkow@24266
   560
val Int_Numeral_Base_Simprocs = assoc_fold_simproc :: zero_one_idom_simproc
wenzelm@23164
   561
  :: Int_Numeral_Simprocs.combine_numerals
wenzelm@23164
   562
  :: Int_Numeral_Simprocs.cancel_numerals;
wenzelm@23164
   563
wenzelm@23164
   564
in
wenzelm@23164
   565
wenzelm@23164
   566
val int_arith_setup =
wenzelm@24093
   567
  LinArith.map_data (fn {add_mono_thms, mult_mono_thms, inj_thms, lessD, neqE, simpset} =>
wenzelm@23164
   568
   {add_mono_thms = add_mono_thms,
wenzelm@23164
   569
    mult_mono_thms = @{thm mult_strict_left_mono} :: @{thm mult_left_mono} :: mult_mono_thms,
wenzelm@23164
   570
    inj_thms = nat_inj_thms @ inj_thms,
haftmann@25481
   571
    lessD = lessD @ [@{thm zless_imp_add1_zle}],
wenzelm@23164
   572
    neqE = neqE,
wenzelm@23164
   573
    simpset = simpset addsimps add_rules
wenzelm@23164
   574
                      addsimprocs Int_Numeral_Base_Simprocs
wenzelm@23164
   575
                      addcongs [if_weak_cong]}) #>
haftmann@24196
   576
  arith_inj_const (@{const_name of_nat}, HOLogic.natT --> HOLogic.intT) #>
haftmann@25919
   577
  arith_discrete @{type_name Int.int}
wenzelm@23164
   578
wenzelm@23164
   579
end;
wenzelm@23164
   580
wenzelm@23164
   581
val fast_int_arith_simproc =
wenzelm@28262
   582
  Simplifier.simproc (the_context ())
wenzelm@23164
   583
  "fast_int_arith" 
wenzelm@23164
   584
     ["(m::'a::{ordered_idom,number_ring}) < n",
wenzelm@23164
   585
      "(m::'a::{ordered_idom,number_ring}) <= n",
wenzelm@24093
   586
      "(m::'a::{ordered_idom,number_ring}) = n"] (K LinArith.lin_arith_simproc);
wenzelm@23164
   587
wenzelm@23164
   588
Addsimprocs [fast_int_arith_simproc];