--- a/ind_syntax.ML Tue Oct 24 14:59:17 1995 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,124 +0,0 @@
-(* Title: HOL/ind_syntax.ML
- ID: $Id$
- Author: Lawrence C Paulson, Cambridge University Computer Laboratory
- Copyright 1994 University of Cambridge
-
-Abstract Syntax functions for Inductive Definitions
-See also hologic.ML and ../Pure/section-utils.ML
-*)
-
-(*The structure protects these items from redeclaration (somewhat!). The
- datatype definitions in theory files refer to these items by name!
-*)
-structure Ind_Syntax =
-struct
-
-(** Abstract syntax definitions for HOL **)
-
-open HOLogic;
-
-fun Int_const T =
- let val sT = mk_setT T
- in Const("op Int", [sT,sT]--->sT) end;
-
-fun mk_exists (Free(x,T),P) = exists_const T $ (absfree (x,T,P));
-
-fun mk_all (Free(x,T),P) = all_const T $ (absfree (x,T,P));
-
-(*Creates All(%v.v:A --> P(v)) rather than Ball(A,P) *)
-fun mk_all_imp (A,P) =
- let val T = dest_setT (fastype_of A)
- in all_const T $ Abs("v", T, imp $ (mk_mem (Bound 0, A)) $ (P $ Bound 0))
- end;
-
-(** Cartesian product type **)
-
-val unitT = Type("unit",[]);
-
-fun mk_prod (T1,T2) = Type("*", [T1,T2]);
-
-(*Maps the type T1*...*Tn to [T1,...,Tn], if nested to the right*)
-fun factors (Type("*", [T1,T2])) = T1 :: factors T2
- | factors T = [T];
-
-(*Make a correctly typed ordered pair*)
-fun mk_Pair (t1,t2) =
- let val T1 = fastype_of t1
- and T2 = fastype_of t2
- in Const("Pair", [T1, T2] ---> mk_prod(T1,T2)) $ t1 $ t2 end;
-
-fun split_const(Ta,Tb,Tc) =
- Const("split", [[Ta,Tb]--->Tc, mk_prod(Ta,Tb)] ---> Tc);
-
-(*Given u expecting arguments of types [T1,...,Tn], create term of
- type T1*...*Tn => Tc using split. Here * associates to the LEFT*)
-fun ap_split_l Tc u [ ] = Abs("null", unitT, u)
- | ap_split_l Tc u [_] = u
- | ap_split_l Tc u (Ta::Tb::Ts) = ap_split_l Tc (split_const(Ta,Tb,Tc) $ u)
- (mk_prod(Ta,Tb) :: Ts);
-
-(*Given u expecting arguments of types [T1,...,Tn], create term of
- type T1*...*Tn => i using split. Here * associates to the RIGHT*)
-fun ap_split Tc u [ ] = Abs("null", unitT, u)
- | ap_split Tc u [_] = u
- | ap_split Tc u [Ta,Tb] = split_const(Ta,Tb,Tc) $ u
- | ap_split Tc u (Ta::Ts) =
- split_const(Ta, foldr1 mk_prod Ts, Tc) $
- (Abs("v", Ta, ap_split Tc (u $ Bound(length Ts - 2)) Ts));
-
-(** Disjoint sum type **)
-
-fun mk_sum (T1,T2) = Type("+", [T1,T2]);
-val Inl = Const("Inl", dummyT)
-and Inr = Const("Inr", dummyT); (*correct types added later!*)
-(*val elim = Const("case", [iT-->iT, iT-->iT, iT]--->iT)*)
-
-fun summands (Type("+", [T1,T2])) = summands T1 @ summands T2
- | summands T = [T];
-
-(*Given the destination type, fills in correct types of an Inl/Inr nest*)
-fun mend_sum_types (h,T) =
- (case (h,T) of
- (Const("Inl",_) $ h1, Type("+", [T1,T2])) =>
- Const("Inl", T1 --> T) $ (mend_sum_types (h1, T1))
- | (Const("Inr",_) $ h2, Type("+", [T1,T2])) =>
- Const("Inr", T2 --> T) $ (mend_sum_types (h2, T2))
- | _ => h);
-
-
-
-(*simple error-checking in the premises of an inductive definition*)
-fun chk_prem rec_hd (Const("op &",_) $ _ $ _) =
- error"Premises may not be conjuctive"
- | chk_prem rec_hd (Const("op :",_) $ t $ X) =
- deny (Logic.occs(rec_hd,t)) "Recursion term on left of member symbol"
- | chk_prem rec_hd t =
- deny (Logic.occs(rec_hd,t)) "Recursion term in side formula";
-
-(*Return the conclusion of a rule, of the form t:X*)
-fun rule_concl rl =
- let val Const("Trueprop",_) $ (Const("op :",_) $ t $ X) =
- Logic.strip_imp_concl rl
- in (t,X) end;
-
-(*As above, but return error message if bad*)
-fun rule_concl_msg sign rl = rule_concl rl
- handle Bind => error ("Ill-formed conclusion of introduction rule: " ^
- Sign.string_of_term sign rl);
-
-(*For simplifying the elimination rule*)
-val sumprod_free_SEs =
- Pair_inject ::
- map make_elim [(*Inl_neq_Inr, Inr_neq_Inl, Inl_inject, Inr_inject*)];
-
-(*For deriving cases rules.
- read_instantiate replaces a propositional variable by a formula variable*)
-val equals_CollectD =
- read_instantiate [("W","?Q")]
- (make_elim (equalityD1 RS subsetD RS CollectD));
-
-(*Delete needless equality assumptions*)
-val refl_thin = prove_goal HOL.thy "!!P. [| a=a; P |] ==> P"
- (fn _ => [assume_tac 1]);
-
-end;