paulson@5562
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(* Title: HOL/Integ/Int.ML
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paulson@5562
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ID: $Id$
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paulson@5562
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Author: Lawrence C Paulson, Cambridge University Computer Laboratory
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paulson@5562
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Copyright 1998 University of Cambridge
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Type "int" is a linear order
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paulson@6866
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paulson@6866
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And many further lemmas
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*)
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paulson@5562
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wenzelm@7707
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paulson@11868
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Goal "int 0 = (0::int)";
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paulson@11868
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by (simp_tac (simpset() addsimps [Zero_int_def]) 1);
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paulson@11868
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qed "int_0";
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paulson@11868
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paulson@11868
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Goal "int 1 = 1";
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paulson@11868
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by (simp_tac (simpset() addsimps [One_int_def]) 1);
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paulson@11868
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qed "int_1";
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paulson@11868
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paulson@11868
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Goal "int (Suc 0) = 1";
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paulson@11868
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by (simp_tac (simpset() addsimps [One_int_def, One_nat_def]) 1);
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paulson@11868
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qed "int_Suc0_eq_1";
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paulson@11868
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paulson@11868
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Goalw [zdiff_def,zless_def] "neg x = (x < 0)";
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paulson@11868
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by Auto_tac;
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paulson@11868
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qed "neg_eq_less_0";
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paulson@11868
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paulson@11868
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Goalw [zle_def] "(~neg x) = (0 <= x)";
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paulson@11868
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by (simp_tac (simpset() addsimps [neg_eq_less_0]) 1);
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paulson@11868
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qed "not_neg_eq_ge_0";
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paulson@11868
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paulson@11868
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(** Needed to simplify inequalities when Numeral1 can get simplified to 1 **)
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paulson@11868
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Goal "~ neg 0";
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paulson@11868
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by (simp_tac (simpset() addsimps [One_int_def, neg_eq_less_0]) 1);
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paulson@11868
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qed "not_neg_0";
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paulson@11868
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paulson@11868
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Goal "~ neg 1";
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paulson@11868
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by (simp_tac (simpset() addsimps [One_int_def, neg_eq_less_0]) 1);
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paulson@11868
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qed "not_neg_1";
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paulson@11868
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paulson@11868
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Goal "iszero 0";
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paulson@11868
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by (simp_tac (simpset() addsimps [iszero_def]) 1);
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qed "iszero_0";
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paulson@11868
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Goal "~ iszero 1";
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by (simp_tac (simpset() addsimps [Zero_int_def, One_int_def, One_nat_def,
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iszero_def]) 1);
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qed "not_iszero_1";
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Goal "0 < (1::int)";
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by (simp_tac (simpset() addsimps [Zero_int_def, One_int_def, One_nat_def]) 1);
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paulson@11868
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qed "int_0_less_1";
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paulson@11868
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paulson@11868
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Goal "0 \\<noteq> (1::int)";
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paulson@11868
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by (simp_tac (simpset() addsimps [Zero_int_def, One_int_def, One_nat_def]) 1);
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paulson@11868
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qed "int_0_neq_1";
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paulson@11868
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Addsimps [int_0, int_1, int_0_neq_1];
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paulson@11868
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paulson@11868
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(*** Abel_Cancel simproc on the integers ***)
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wenzelm@7707
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(* Lemmas needed for the simprocs *)
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(*Deletion of other terms in the formula, seeking the -x at the front of z*)
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wenzelm@7707
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Goal "((x::int) + (y + z) = y + u) = ((x + z) = u)";
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wenzelm@7707
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by (stac zadd_left_commute 1);
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wenzelm@7707
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by (rtac zadd_left_cancel 1);
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qed "zadd_cancel_21";
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wenzelm@7707
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wenzelm@7707
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(*A further rule to deal with the case that
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everything gets cancelled on the right.*)
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wenzelm@7707
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Goal "((x::int) + (y + z) = y) = (x = -z)";
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wenzelm@7707
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by (stac zadd_left_commute 1);
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by (res_inst_tac [("t", "y")] (zadd_0_right RS subst) 1
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wenzelm@7707
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THEN stac zadd_left_cancel 1);
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wenzelm@7707
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by (simp_tac (simpset() addsimps [eq_zdiff_eq RS sym]) 1);
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wenzelm@7707
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qed "zadd_cancel_end";
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wenzelm@7707
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wenzelm@7707
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wenzelm@7707
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structure Int_Cancel_Data =
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struct
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val ss = HOL_ss
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val eq_reflection = eq_reflection
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wenzelm@9436
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val sg_ref = Sign.self_ref (Theory.sign_of (the_context ()))
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val T = HOLogic.intT
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val zero = Const ("0", HOLogic.intT)
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val restrict_to_left = restrict_to_left
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val add_cancel_21 = zadd_cancel_21
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val add_cancel_end = zadd_cancel_end
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val add_left_cancel = zadd_left_cancel
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val add_assoc = zadd_assoc
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val add_commute = zadd_commute
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val add_left_commute = zadd_left_commute
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val add_0 = zadd_0
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val add_0_right = zadd_0_right
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val eq_diff_eq = eq_zdiff_eq
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val eqI_rules = [zless_eqI, zeq_eqI, zle_eqI]
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fun dest_eqI th =
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#1 (HOLogic.dest_bin "op =" HOLogic.boolT
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(HOLogic.dest_Trueprop (concl_of th)))
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val diff_def = zdiff_def
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val minus_add_distrib = zminus_zadd_distrib
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wenzelm@7707
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val minus_minus = zminus_zminus
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val minus_0 = zminus_0
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val add_inverses = [zadd_zminus_inverse, zadd_zminus_inverse2]
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wenzelm@7707
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val cancel_simps = [zadd_zminus_cancel, zminus_zadd_cancel]
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end;
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structure Int_Cancel = Abel_Cancel (Int_Cancel_Data);
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wenzelm@7707
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wenzelm@7707
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Addsimprocs [Int_Cancel.sum_conv, Int_Cancel.rel_conv];
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wenzelm@7707
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wenzelm@7707
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wenzelm@7707
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wenzelm@7707
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(*** misc ***)
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wenzelm@7707
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paulson@8785
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Goal "- (z - y) = y - (z::int)";
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paulson@8785
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by (Simp_tac 1);
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paulson@8785
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qed "zminus_zdiff_eq";
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paulson@8785
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Addsimps [zminus_zdiff_eq];
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paulson@8785
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Goal "(w<z) = neg(w-z)";
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by (simp_tac (simpset() addsimps [zless_def]) 1);
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qed "zless_eq_neg";
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paulson@5562
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paulson@5562
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Goal "(w=z) = iszero(w-z)";
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paulson@5562
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by (simp_tac (simpset() addsimps [iszero_def, zdiff_eq_eq]) 1);
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qed "eq_eq_iszero";
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paulson@5562
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paulson@5562
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Goal "(w<=z) = (~ neg(z-w))";
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paulson@5562
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by (simp_tac (simpset() addsimps [zle_def, zless_def]) 1);
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paulson@5562
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qed "zle_eq_not_neg";
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(** Inequality reasoning **)
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Goal "(w < z + (1::int)) = (w<z | w=z)";
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by (auto_tac (claset(),
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simpset() addsimps [zless_iff_Suc_zadd, int_Suc,
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gr0_conv_Suc, zero_reorient]));
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paulson@11868
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by (res_inst_tac [("x","Suc n")] exI 1);
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paulson@11868
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by (simp_tac (simpset() addsimps [int_Suc]) 1);
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paulson@11868
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qed "zless_add1_eq";
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paulson@5593
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paulson@11868
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Goal "(w + (1::int) <= z) = (w<z)";
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paulson@11868
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by (asm_full_simp_tac (simpset() addsimps [zle_def, zless_add1_eq]) 1);
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paulson@11868
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by (auto_tac (claset() addIs [zle_anti_sym],
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paulson@11868
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simpset() addsimps [order_less_imp_le, symmetric zle_def]));
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paulson@11868
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qed "add1_zle_eq";
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paulson@5593
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paulson@11868
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Goal "((1::int) + w <= z) = (w<z)";
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paulson@11868
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by (stac zadd_commute 1);
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paulson@11868
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by (rtac add1_zle_eq 1);
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paulson@11868
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qed "add1_left_zle_eq";
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paulson@5593
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paulson@5593
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paulson@5562
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(*** Monotonicity results ***)
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paulson@5562
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paulson@5562
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Goal "(v+z < w+z) = (v < (w::int))";
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paulson@5582
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_right_cancel_zless";
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paulson@5562
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paulson@5562
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Goal "(z+v < z+w) = (v < (w::int))";
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paulson@5582
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_left_cancel_zless";
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paulson@5562
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paulson@5562
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Addsimps [zadd_right_cancel_zless, zadd_left_cancel_zless];
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paulson@5562
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paulson@5562
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Goal "(v+z <= w+z) = (v <= (w::int))";
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paulson@5582
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_right_cancel_zle";
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paulson@5562
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paulson@5562
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Goal "(z+v <= z+w) = (v <= (w::int))";
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paulson@5582
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_left_cancel_zle";
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paulson@5562
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paulson@5562
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Addsimps [zadd_right_cancel_zle, zadd_left_cancel_zle];
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paulson@5562
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paulson@5562
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(*"v<=w ==> v+z <= w+z"*)
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paulson@5562
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bind_thm ("zadd_zless_mono1", zadd_right_cancel_zless RS iffD2);
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paulson@5562
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paulson@6998
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(*"v<=w ==> z+v <= z+w"*)
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paulson@6998
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bind_thm ("zadd_zless_mono2", zadd_left_cancel_zless RS iffD2);
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paulson@6998
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paulson@5562
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(*"v<=w ==> v+z <= w+z"*)
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paulson@5562
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bind_thm ("zadd_zle_mono1", zadd_right_cancel_zle RS iffD2);
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paulson@5562
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paulson@6998
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(*"v<=w ==> z+v <= z+w"*)
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paulson@6998
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bind_thm ("zadd_zle_mono2", zadd_left_cancel_zle RS iffD2);
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paulson@6998
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paulson@7081
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Goal "[| w'<=w; z'<=z |] ==> w' + z' <= w + (z::int)";
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paulson@5562
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by (etac (zadd_zle_mono1 RS zle_trans) 1);
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paulson@5562
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_zle_mono";
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paulson@5562
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paulson@7081
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Goal "[| w'<w; z'<=z |] ==> w' + z' < w + (z::int)";
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paulson@10646
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by (etac (zadd_zless_mono1 RS order_less_le_trans) 1);
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paulson@5562
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by (Simp_tac 1);
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paulson@5562
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qed "zadd_zless_mono";
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paulson@5562
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paulson@5562
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paulson@5562
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(*** Comparison laws ***)
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paulson@5562
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paulson@5562
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Goal "(- x < - y) = (y < (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zless_def, zdiff_def] @ zadd_ac) 1);
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paulson@5562
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qed "zminus_zless_zminus";
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paulson@5562
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Addsimps [zminus_zless_zminus];
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paulson@5562
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paulson@5562
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Goal "(- x <= - y) = (y <= (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zle_def]) 1);
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paulson@5562
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qed "zminus_zle_zminus";
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paulson@5562
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Addsimps [zminus_zle_zminus];
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paulson@5562
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paulson@5562
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(** The next several equations can make the simplifier loop! **)
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paulson@5562
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paulson@5562
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Goal "(x < - y) = (y < - (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zless_def, zdiff_def] @ zadd_ac) 1);
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paulson@5562
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qed "zless_zminus";
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paulson@5562
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paulson@5562
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Goal "(- x < y) = (- y < (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zless_def, zdiff_def] @ zadd_ac) 1);
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paulson@5562
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qed "zminus_zless";
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paulson@5562
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paulson@5562
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Goal "(x <= - y) = (y <= - (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zle_def, zminus_zless]) 1);
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paulson@5562
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qed "zle_zminus";
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paulson@5562
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paulson@5562
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Goal "(- x <= y) = (- y <= (x::int))";
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paulson@5582
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by (simp_tac (simpset() addsimps [zle_def, zless_zminus]) 1);
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paulson@5562
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qed "zminus_zle";
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paulson@5562
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paulson@6917
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Goal "(x = - y) = (y = - (x::int))";
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paulson@6917
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by Auto_tac;
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paulson@6917
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qed "equation_zminus";
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paulson@6917
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paulson@6917
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Goal "(- x = y) = (- (y::int) = x)";
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paulson@6917
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by Auto_tac;
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paulson@6917
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qed "zminus_equation";
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paulson@6917
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paulson@11868
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paulson@11868
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(** Instances of the equations above, for zero **)
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paulson@11868
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paulson@11868
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(*instantiate a variable to zero and simplify*)
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paulson@11868
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fun zero_instance v th = simplify (simpset()) (inst v "0" th);
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paulson@11868
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paulson@11868
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Addsimps [zero_instance "x" zless_zminus,
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paulson@11868
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zero_instance "y" zminus_zless,
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paulson@11868
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zero_instance "x" zle_zminus,
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paulson@11868
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zero_instance "y" zminus_zle,
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paulson@11868
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zero_instance "x" equation_zminus,
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paulson@11868
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zero_instance "y" zminus_equation];
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paulson@11868
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256 |
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paulson@11868
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257 |
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paulson@11868
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258 |
Goal "- (int (Suc n)) < 0";
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paulson@5582
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259 |
by (simp_tac (simpset() addsimps [zless_def]) 1);
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paulson@5562
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260 |
qed "negative_zless_0";
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paulson@5562
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261 |
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paulson@5582
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262 |
Goal "- (int (Suc n)) < int m";
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paulson@10646
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263 |
by (rtac (negative_zless_0 RS order_less_le_trans) 1);
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paulson@5562
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264 |
by (Simp_tac 1);
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paulson@5562
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265 |
qed "negative_zless";
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paulson@5562
|
266 |
AddIffs [negative_zless];
|
paulson@5562
|
267 |
|
paulson@11868
|
268 |
Goal "- int n <= 0";
|
paulson@5582
|
269 |
by (simp_tac (simpset() addsimps [zminus_zle]) 1);
|
paulson@5562
|
270 |
qed "negative_zle_0";
|
paulson@5562
|
271 |
|
paulson@5582
|
272 |
Goal "- int n <= int m";
|
paulson@5582
|
273 |
by (simp_tac (simpset() addsimps [zless_def, zle_def, zdiff_def, zadd_int]) 1);
|
paulson@5562
|
274 |
qed "negative_zle";
|
paulson@5562
|
275 |
AddIffs [negative_zle];
|
paulson@5562
|
276 |
|
paulson@11868
|
277 |
Goal "~(0 <= - (int (Suc n)))";
|
paulson@5562
|
278 |
by (stac zle_zminus 1);
|
paulson@5562
|
279 |
by (Simp_tac 1);
|
paulson@5562
|
280 |
qed "not_zle_0_negative";
|
paulson@5562
|
281 |
Addsimps [not_zle_0_negative];
|
paulson@5562
|
282 |
|
paulson@5582
|
283 |
Goal "(int n <= - int m) = (n = 0 & m = 0)";
|
paulson@5562
|
284 |
by Safe_tac;
|
paulson@5562
|
285 |
by (Simp_tac 3);
|
paulson@5562
|
286 |
by (dtac (zle_zminus RS iffD1) 2);
|
paulson@5562
|
287 |
by (ALLGOALS (dtac (negative_zle_0 RSN(2,zle_trans))));
|
paulson@5562
|
288 |
by (ALLGOALS Asm_full_simp_tac);
|
paulson@5562
|
289 |
qed "int_zle_neg";
|
paulson@5562
|
290 |
|
paulson@5582
|
291 |
Goal "~(int n < - int m)";
|
paulson@5562
|
292 |
by (simp_tac (simpset() addsimps [symmetric zle_def]) 1);
|
paulson@5562
|
293 |
qed "not_int_zless_negative";
|
paulson@5562
|
294 |
|
paulson@5582
|
295 |
Goal "(- int n = int m) = (n = 0 & m = 0)";
|
paulson@5562
|
296 |
by (rtac iffI 1);
|
paulson@5562
|
297 |
by (rtac (int_zle_neg RS iffD1) 1);
|
paulson@5562
|
298 |
by (dtac sym 1);
|
paulson@5562
|
299 |
by (ALLGOALS Asm_simp_tac);
|
paulson@5562
|
300 |
qed "negative_eq_positive";
|
paulson@5562
|
301 |
|
paulson@5562
|
302 |
Addsimps [negative_eq_positive, not_int_zless_negative];
|
paulson@5562
|
303 |
|
paulson@5562
|
304 |
|
paulson@5582
|
305 |
Goal "(w <= z) = (EX n. z = w + int n)";
|
paulson@11868
|
306 |
by (auto_tac (claset() addIs [inst "x" "0::nat" exI]
|
paulson@11868
|
307 |
addSIs [not_sym RS not0_implies_Suc],
|
wenzelm@10472
|
308 |
simpset() addsimps [zless_iff_Suc_zadd, int_le_less]));
|
paulson@5562
|
309 |
qed "zle_iff_zadd";
|
paulson@5562
|
310 |
|
paulson@9945
|
311 |
Goal "abs (int m) = int m";
|
paulson@9945
|
312 |
by (simp_tac (simpset() addsimps [zabs_def]) 1);
|
paulson@9945
|
313 |
qed "abs_int_eq";
|
paulson@9945
|
314 |
Addsimps [abs_int_eq];
|
paulson@9945
|
315 |
|
paulson@5562
|
316 |
|
paulson@5562
|
317 |
(**** nat: magnitide of an integer, as a natural number ****)
|
paulson@5562
|
318 |
|
paulson@5582
|
319 |
Goalw [nat_def] "nat(int n) = n";
|
paulson@5562
|
320 |
by Auto_tac;
|
paulson@7009
|
321 |
qed "nat_int";
|
paulson@11868
|
322 |
Addsimps [nat_int];
|
paulson@5562
|
323 |
|
paulson@11868
|
324 |
Goalw [nat_def] "nat(- (int n)) = 0";
|
paulson@5562
|
325 |
by (auto_tac (claset(),
|
paulson@11868
|
326 |
simpset() addsimps [neg_eq_less_0, zero_reorient, zminus_zless]));
|
paulson@7009
|
327 |
qed "nat_zminus_int";
|
paulson@11868
|
328 |
Addsimps [nat_zminus_int];
|
paulson@5562
|
329 |
|
paulson@11868
|
330 |
Goalw [Zero_int_def] "nat 0 = 0";
|
paulson@11868
|
331 |
by (rtac nat_int 1);
|
paulson@11868
|
332 |
qed "nat_zero";
|
paulson@11868
|
333 |
Addsimps [nat_zero];
|
paulson@5562
|
334 |
|
paulson@5582
|
335 |
Goal "~ neg z ==> int (nat z) = z";
|
paulson@11868
|
336 |
by (dtac (not_neg_eq_ge_0 RS iffD1) 1);
|
paulson@5562
|
337 |
by (dtac zle_imp_zless_or_eq 1);
|
paulson@5562
|
338 |
by (auto_tac (claset(), simpset() addsimps [zless_iff_Suc_zadd]));
|
paulson@5562
|
339 |
qed "not_neg_nat";
|
paulson@5562
|
340 |
|
paulson@7081
|
341 |
Goal "neg x ==> EX n. x = - (int (Suc n))";
|
paulson@5562
|
342 |
by (auto_tac (claset(),
|
paulson@11868
|
343 |
simpset() addsimps [neg_eq_less_0, zless_iff_Suc_zadd,
|
paulson@5562
|
344 |
zdiff_eq_eq RS sym, zdiff_def]));
|
paulson@5562
|
345 |
qed "negD";
|
paulson@5562
|
346 |
|
paulson@5562
|
347 |
Goalw [nat_def] "neg z ==> nat z = 0";
|
paulson@5562
|
348 |
by Auto_tac;
|
paulson@5562
|
349 |
qed "neg_nat";
|
paulson@5562
|
350 |
|
paulson@7518
|
351 |
Goal "(m < nat z) = (int m < z)";
|
paulson@7518
|
352 |
by (case_tac "neg z" 1);
|
paulson@7518
|
353 |
by (etac (not_neg_nat RS subst) 2);
|
paulson@7518
|
354 |
by (auto_tac (claset(), simpset() addsimps [neg_nat]));
|
paulson@7518
|
355 |
by (auto_tac (claset() addDs [order_less_trans],
|
paulson@11868
|
356 |
simpset() addsimps [neg_eq_less_0]));
|
paulson@7518
|
357 |
qed "zless_nat_eq_int_zless";
|
paulson@7518
|
358 |
|
paulson@12613
|
359 |
Goal "0 <= z ==> int (nat z) = z";
|
paulson@12613
|
360 |
by (asm_full_simp_tac
|
paulson@12613
|
361 |
(simpset() addsimps [neg_eq_less_0, zle_def, not_neg_nat]) 1);
|
paulson@12613
|
362 |
qed "nat_0_le";
|
paulson@12613
|
363 |
|
paulson@11868
|
364 |
Goal "z <= 0 ==> nat z = 0";
|
paulson@7518
|
365 |
by (auto_tac (claset(),
|
paulson@11868
|
366 |
simpset() addsimps [order_le_less, neg_eq_less_0,
|
paulson@7518
|
367 |
zle_def, neg_nat]));
|
paulson@12613
|
368 |
qed "nat_le_0";
|
paulson@12613
|
369 |
Addsimps [nat_0_le, nat_le_0];
|
paulson@7518
|
370 |
|
paulson@11868
|
371 |
(*An alternative condition is 0 <= w *)
|
paulson@11868
|
372 |
Goal "0 < z ==> (nat w < nat z) = (w < z)";
|
paulson@6866
|
373 |
by (stac (zless_int RS sym) 1);
|
paulson@11868
|
374 |
by (asm_simp_tac (simpset() addsimps [not_neg_nat, not_neg_eq_ge_0,
|
paulson@6866
|
375 |
order_le_less]) 1);
|
paulson@6866
|
376 |
by (case_tac "neg w" 1);
|
paulson@6866
|
377 |
by (asm_simp_tac (simpset() addsimps [not_neg_nat]) 2);
|
paulson@11868
|
378 |
by (asm_full_simp_tac (simpset() addsimps [neg_eq_less_0, neg_nat]) 1);
|
paulson@6866
|
379 |
by (blast_tac (claset() addIs [order_less_trans]) 1);
|
paulson@6917
|
380 |
val lemma = result();
|
paulson@6917
|
381 |
|
paulson@11868
|
382 |
Goal "(nat w < nat z) = (0 < z & w < z)";
|
paulson@11868
|
383 |
by (case_tac "0 < z" 1);
|
paulson@12613
|
384 |
by (auto_tac (claset(), simpset() addsimps [lemma, linorder_not_less]));
|
paulson@6917
|
385 |
qed "zless_nat_conj";
|
paulson@6917
|
386 |
|
paulson@6866
|
387 |
|
paulson@6866
|
388 |
(* a case theorem distinguishing non-negative and negative int *)
|
paulson@5562
|
389 |
|
paulson@6942
|
390 |
val prems = Goal
|
paulson@6942
|
391 |
"[|!! n. z = int n ==> P; !! n. z = - (int (Suc n)) ==> P |] ==> P";
|
paulson@5562
|
392 |
by (case_tac "neg z" 1);
|
paulson@6942
|
393 |
by (fast_tac (claset() addSDs [negD] addSEs prems) 1);
|
paulson@6942
|
394 |
by (dtac (not_neg_nat RS sym) 1);
|
paulson@6942
|
395 |
by (eresolve_tac prems 1);
|
paulson@5562
|
396 |
qed "int_cases";
|
paulson@5562
|
397 |
|
paulson@5562
|
398 |
fun int_case_tac x = res_inst_tac [("z",x)] int_cases;
|
paulson@5562
|
399 |
|
paulson@6866
|
400 |
|
paulson@6866
|
401 |
(*** Monotonicity of Multiplication ***)
|
paulson@6866
|
402 |
|
paulson@6866
|
403 |
Goal "i <= (j::int) ==> i * int k <= j * int k";
|
paulson@6866
|
404 |
by (induct_tac "k" 1);
|
paulson@11868
|
405 |
by (stac int_Suc 2);
|
paulson@6866
|
406 |
by (ALLGOALS
|
paulson@11868
|
407 |
(asm_simp_tac (simpset() addsimps [zadd_zmult_distrib2, zadd_zle_mono,
|
paulson@11868
|
408 |
int_Suc0_eq_1])));
|
paulson@6866
|
409 |
val lemma = result();
|
paulson@6866
|
410 |
|
paulson@11868
|
411 |
Goal "[| i <= j; (0::int) <= k |] ==> i*k <= j*k";
|
paulson@6866
|
412 |
by (res_inst_tac [("t", "k")] (not_neg_nat RS subst) 1);
|
paulson@6866
|
413 |
by (etac lemma 2);
|
paulson@11868
|
414 |
by (full_simp_tac (simpset() addsimps [not_neg_eq_ge_0]) 1);
|
paulson@6866
|
415 |
qed "zmult_zle_mono1";
|
paulson@6866
|
416 |
|
paulson@11868
|
417 |
Goal "[| i <= j; k <= (0::int) |] ==> j*k <= i*k";
|
paulson@6866
|
418 |
by (rtac (zminus_zle_zminus RS iffD1) 1);
|
paulson@6866
|
419 |
by (asm_simp_tac (simpset() addsimps [zmult_zminus_right RS sym,
|
paulson@6866
|
420 |
zmult_zle_mono1, zle_zminus]) 1);
|
paulson@6866
|
421 |
qed "zmult_zle_mono1_neg";
|
paulson@6866
|
422 |
|
paulson@11868
|
423 |
Goal "[| i <= j; (0::int) <= k |] ==> k*i <= k*j";
|
paulson@6942
|
424 |
by (dtac zmult_zle_mono1 1);
|
paulson@6942
|
425 |
by (ALLGOALS (asm_full_simp_tac (simpset() addsimps [zmult_commute])));
|
paulson@6942
|
426 |
qed "zmult_zle_mono2";
|
paulson@6942
|
427 |
|
paulson@11868
|
428 |
Goal "[| i <= j; k <= (0::int) |] ==> k*j <= k*i";
|
paulson@6942
|
429 |
by (dtac zmult_zle_mono1_neg 1);
|
paulson@6942
|
430 |
by (ALLGOALS (asm_full_simp_tac (simpset() addsimps [zmult_commute])));
|
paulson@6942
|
431 |
qed "zmult_zle_mono2_neg";
|
paulson@6942
|
432 |
|
paulson@6990
|
433 |
(* <= monotonicity, BOTH arguments*)
|
paulson@11868
|
434 |
Goal "[| i <= j; k <= l; (0::int) <= j; (0::int) <= k |] ==> i*k <= j*l";
|
paulson@6866
|
435 |
by (etac (zmult_zle_mono1 RS order_trans) 1);
|
paulson@6866
|
436 |
by (assume_tac 1);
|
paulson@6990
|
437 |
by (etac zmult_zle_mono2 1);
|
paulson@6990
|
438 |
by (assume_tac 1);
|
paulson@6866
|
439 |
qed "zmult_zle_mono";
|
paulson@6866
|
440 |
|
paulson@6866
|
441 |
|
paulson@6866
|
442 |
(** strict, in 1st argument; proof is by induction on k>0 **)
|
paulson@6866
|
443 |
|
paulson@6866
|
444 |
Goal "i<j ==> 0<k --> int k * i < int k * j";
|
paulson@6866
|
445 |
by (induct_tac "k" 1);
|
paulson@11868
|
446 |
by (stac int_Suc 2);
|
paulson@6866
|
447 |
by (case_tac "n=0" 2);
|
paulson@6866
|
448 |
by (ALLGOALS (asm_full_simp_tac
|
paulson@6866
|
449 |
(simpset() addsimps [zadd_zmult_distrib, zadd_zless_mono,
|
paulson@11868
|
450 |
int_Suc0_eq_1, order_le_less])));
|
paulson@11868
|
451 |
val lemma = result();
|
paulson@6866
|
452 |
|
paulson@11868
|
453 |
Goal "[| i<j; (0::int) < k |] ==> k*i < k*j";
|
paulson@6866
|
454 |
by (res_inst_tac [("t", "k")] (not_neg_nat RS subst) 1);
|
paulson@11868
|
455 |
by (etac (lemma RS mp) 2);
|
paulson@11868
|
456 |
by (asm_simp_tac (simpset() addsimps [not_neg_eq_ge_0,
|
paulson@6866
|
457 |
order_le_less]) 1);
|
paulson@6917
|
458 |
by (forward_tac [conjI RS (zless_nat_conj RS iffD2)] 1);
|
paulson@6866
|
459 |
by Auto_tac;
|
paulson@6866
|
460 |
qed "zmult_zless_mono2";
|
paulson@6866
|
461 |
|
paulson@11868
|
462 |
Goal "[| i<j; (0::int) < k |] ==> i*k < j*k";
|
paulson@6866
|
463 |
by (dtac zmult_zless_mono2 1);
|
paulson@6866
|
464 |
by (ALLGOALS (asm_full_simp_tac (simpset() addsimps [zmult_commute])));
|
paulson@6866
|
465 |
qed "zmult_zless_mono1";
|
paulson@6866
|
466 |
|
paulson@6990
|
467 |
(* < monotonicity, BOTH arguments*)
|
paulson@11868
|
468 |
Goal "[| i < j; k < l; (0::int) < j; (0::int) < k |] ==> i*k < j*l";
|
paulson@6990
|
469 |
by (etac (zmult_zless_mono1 RS order_less_trans) 1);
|
paulson@6990
|
470 |
by (assume_tac 1);
|
paulson@6990
|
471 |
by (etac zmult_zless_mono2 1);
|
paulson@6990
|
472 |
by (assume_tac 1);
|
paulson@6990
|
473 |
qed "zmult_zless_mono";
|
paulson@6990
|
474 |
|
paulson@11868
|
475 |
Goal "[| i<j; k < (0::int) |] ==> j*k < i*k";
|
paulson@6866
|
476 |
by (rtac (zminus_zless_zminus RS iffD1) 1);
|
paulson@6866
|
477 |
by (asm_simp_tac (simpset() addsimps [zmult_zminus_right RS sym,
|
paulson@6866
|
478 |
zmult_zless_mono1, zless_zminus]) 1);
|
paulson@6866
|
479 |
qed "zmult_zless_mono1_neg";
|
paulson@6866
|
480 |
|
paulson@11868
|
481 |
Goal "[| i<j; k < (0::int) |] ==> k*j < k*i";
|
paulson@6866
|
482 |
by (rtac (zminus_zless_zminus RS iffD1) 1);
|
paulson@6866
|
483 |
by (asm_simp_tac (simpset() addsimps [zmult_zminus RS sym,
|
paulson@6866
|
484 |
zmult_zless_mono2, zless_zminus]) 1);
|
paulson@6866
|
485 |
qed "zmult_zless_mono2_neg";
|
paulson@6866
|
486 |
|
paulson@6866
|
487 |
|
paulson@11868
|
488 |
Goal "(m*n = (0::int)) = (m = 0 | n = 0)";
|
paulson@11868
|
489 |
by (case_tac "m < (0::int)" 1);
|
paulson@6866
|
490 |
by (auto_tac (claset(),
|
paulson@6866
|
491 |
simpset() addsimps [linorder_not_less, order_le_less,
|
paulson@6866
|
492 |
linorder_neq_iff]));
|
paulson@6866
|
493 |
by (REPEAT
|
paulson@6866
|
494 |
(force_tac (claset() addDs [zmult_zless_mono1_neg, zmult_zless_mono1],
|
paulson@6866
|
495 |
simpset()) 1));
|
paulson@11868
|
496 |
qed "zmult_eq_0_iff";
|
paulson@11868
|
497 |
AddIffs [zmult_eq_0_iff];
|
paulson@6866
|
498 |
|
paulson@6866
|
499 |
|
paulson@9633
|
500 |
(** Cancellation laws for k*m < k*n and m*k < n*k, also for <= and =,
|
paulson@9633
|
501 |
but not (yet?) for k*m < n*k. **)
|
paulson@9633
|
502 |
|
paulson@11868
|
503 |
Goal "(m*k < n*k) = (((0::int) < k & m<n) | (k < 0 & n<m))";
|
paulson@11868
|
504 |
by (case_tac "k = (0::int)" 1);
|
paulson@9633
|
505 |
by (auto_tac (claset(), simpset() addsimps [linorder_neq_iff,
|
paulson@9633
|
506 |
zmult_zless_mono1, zmult_zless_mono1_neg]));
|
paulson@9633
|
507 |
by (auto_tac (claset(),
|
paulson@9633
|
508 |
simpset() addsimps [linorder_not_less,
|
paulson@9633
|
509 |
inst "y1" "m*k" (linorder_not_le RS sym),
|
paulson@9633
|
510 |
inst "y1" "m" (linorder_not_le RS sym)]));
|
paulson@9633
|
511 |
by (ALLGOALS (etac notE));
|
paulson@10646
|
512 |
by (auto_tac (claset(), simpset() addsimps [order_less_imp_le, zmult_zle_mono1,
|
paulson@9633
|
513 |
zmult_zle_mono1_neg]));
|
paulson@6866
|
514 |
qed "zmult_zless_cancel2";
|
paulson@6866
|
515 |
|
paulson@9633
|
516 |
|
paulson@11868
|
517 |
Goal "(k*m < k*n) = (((0::int) < k & m<n) | (k < 0 & n<m))";
|
paulson@9633
|
518 |
by (simp_tac (simpset() addsimps [inst "z" "k" zmult_commute,
|
paulson@9633
|
519 |
zmult_zless_cancel2]) 1);
|
paulson@6866
|
520 |
qed "zmult_zless_cancel1";
|
paulson@6866
|
521 |
|
paulson@11868
|
522 |
Goal "(m*k <= n*k) = (((0::int) < k --> m<=n) & (k < 0 --> n<=m))";
|
paulson@9633
|
523 |
by (simp_tac (simpset() addsimps [linorder_not_less RS sym,
|
paulson@9633
|
524 |
zmult_zless_cancel2]) 1);
|
paulson@6866
|
525 |
qed "zmult_zle_cancel2";
|
paulson@6866
|
526 |
|
paulson@11868
|
527 |
Goal "(k*m <= k*n) = (((0::int) < k --> m<=n) & (k < 0 --> n<=m))";
|
paulson@9633
|
528 |
by (simp_tac (simpset() addsimps [linorder_not_less RS sym,
|
paulson@9633
|
529 |
zmult_zless_cancel1]) 1);
|
paulson@6866
|
530 |
qed "zmult_zle_cancel1";
|
paulson@6866
|
531 |
|
paulson@11868
|
532 |
Goal "(m*k = n*k) = (k = (0::int) | m=n)";
|
paulson@6866
|
533 |
by (cut_facts_tac [linorder_less_linear] 1);
|
paulson@6866
|
534 |
by Safe_tac;
|
paulson@9633
|
535 |
by Auto_tac;
|
paulson@6866
|
536 |
by (REPEAT
|
paulson@6866
|
537 |
(force_tac (claset() addD2 ("mono_neg", zmult_zless_mono1_neg)
|
paulson@6866
|
538 |
addD2 ("mono_pos", zmult_zless_mono1),
|
paulson@6866
|
539 |
simpset() addsimps [linorder_neq_iff]) 1));
|
paulson@9633
|
540 |
|
paulson@6866
|
541 |
qed "zmult_cancel2";
|
paulson@6866
|
542 |
|
paulson@11868
|
543 |
Goal "(k*m = k*n) = (k = (0::int) | m=n)";
|
paulson@9633
|
544 |
by (simp_tac (simpset() addsimps [inst "z" "k" zmult_commute,
|
paulson@9633
|
545 |
zmult_cancel2]) 1);
|
paulson@6866
|
546 |
qed "zmult_cancel1";
|
paulson@6866
|
547 |
Addsimps [zmult_cancel1, zmult_cancel2];
|
paulson@11868
|
548 |
|
paulson@11868
|
549 |
|
paulson@11868
|
550 |
(*Analogous to zadd_int*)
|
paulson@11868
|
551 |
Goal "n<=m --> int m - int n = int (m-n)";
|
paulson@11868
|
552 |
by (induct_thm_tac diff_induct "m n" 1);
|
paulson@11868
|
553 |
by (auto_tac (claset(), simpset() addsimps [int_Suc, symmetric zdiff_def]));
|
paulson@11868
|
554 |
qed_spec_mp "zdiff_int";
|