List.ML
changeset 128 89669c58e506
parent 113 0b9b8eb74101
child 171 16c4ea954511
--- a/List.ML	Thu Aug 25 10:47:33 1994 +0200
+++ b/List.ML	Thu Aug 25 11:01:45 1994 +0200
@@ -3,60 +3,43 @@
     Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
     Copyright   1993  University of Cambridge
 
-For List.thy.  
+Definition of type 'a list by a least fixed point
 *)
 
 open List;
 
-(** the list functional **)
-
-goalw List.thy [List_Fun_def] "mono(List_Fun(A))";
-by (REPEAT (ares_tac [monoI, subset_refl, usum_mono, uprod_mono] 1));
-val List_Fun_mono = result();
+val list_con_defs = [NIL_def, CONS_def];
 
-goalw List.thy [List_Fun_def]
-    "!!A B. A<=B ==> List_Fun(A,Z) <= List_Fun(B,Z)";
-by (REPEAT (ares_tac [subset_refl, usum_mono, uprod_mono] 1));
-val List_Fun_mono2 = result();
-
-(*This justifies using List in other recursive type definitions*)
-goalw List.thy [List_def] "!!A B. A<=B ==> List(A) <= List(B)";
-by (rtac lfp_mono 1);
-by (etac List_Fun_mono2 1);
-val List_mono = result();
-
-(** Type checking rules -- List creates well-founded sets **)
+goal List.thy "list(A) = {Numb(0)} <+> (A <*> list(A))";
+let val rew = rewrite_rule list_con_defs in  
+by (fast_tac (univ_cs addSIs (equalityI :: map rew list.intrs)
+                      addEs [rew list.elim]) 1)
+end;
+val list_unfold = result();
 
-val prems = goalw List.thy [List_def,List_Fun_def] "List(Sexp) <= Sexp";
-by (rtac lfp_lowerbound 1);
-by (fast_tac (univ_cs addIs [Sexp_NumbI,Sexp_In0I,Sexp_In1I,Sexp_SconsI]) 1);
-val List_Sexp = result();
-
-(* A <= Sexp ==> List(A) <= Sexp *)
-val List_subset_Sexp = standard
-    (List_mono RS (List_Sexp RSN (2,subset_trans)));
-
-(** Induction **)
+(*This justifies using list in other recursive type definitions*)
+goalw List.thy list.defs "!!A B. A<=B ==> list(A) <= list(B)";
+by (rtac lfp_mono 1);
+by (REPEAT (ares_tac basic_monos 1));
+val list_mono = result();
 
-(*Induction for the set List(A) *)
-val major::prems = goalw List.thy [NIL_def,CONS_def]
-    "[| M: List(A);  P(NIL);   \
-\       !!M N. [| M: A;  N: List(A);  P(N) |] ==> P(CONS(M,N)) |]  \
-\    ==> P(M)";
-by (rtac (major RS (List_def RS def_induct)) 1);
-by (rtac List_Fun_mono 1);
-by (rewtac List_Fun_def);
-by (fast_tac (set_cs addIs prems addEs [usumE,uprodE]) 1);
-val List_induct = result();
+(*Type checking -- list creates well-founded sets*)
+goalw List.thy (list_con_defs @ list.defs) "list(sexp) <= sexp";
+by (rtac lfp_lowerbound 1);
+by (fast_tac (univ_cs addIs sexp.intrs@[sexp_In0I,sexp_In1I]) 1);
+val list_sexp = result();
+
+(* A <= sexp ==> list(A) <= sexp *)
+val list_subset_sexp = standard ([list_mono, list_sexp] MRS subset_trans);
 
 (*Induction for the type 'a list *)
 val prems = goalw List.thy [Nil_def,Cons_def]
     "[| P(Nil);   \
 \       !!x xs. P(xs) ==> P(x # xs) |]  ==> P(l)";
-by (rtac (Rep_List_inverse RS subst) 1);   (*types force good instantiation*)
-by (rtac (Rep_List RS List_induct) 1);
+by (rtac (Rep_list_inverse RS subst) 1);   (*types force good instantiation*)
+by (rtac (Rep_list RS list.induct) 1);
 by (REPEAT (ares_tac prems 1
-     ORELSE eresolve_tac [rangeE, ssubst, Abs_List_inverse RS subst] 1));
+     ORELSE eresolve_tac [rangeE, ssubst, Abs_list_inverse RS subst] 1));
 val list_induct = result();
 
 (*Perform induction on xs. *)
@@ -64,39 +47,21 @@
     EVERY [res_inst_tac [("l",a)] list_induct M,
 	   rename_last_tac a ["1"] (M+1)];
 
-(** Introduction rules for List constructors **)
-
-val List_unfold = rewrite_rule [List_Fun_def]
-	 (List_Fun_mono RS (List_def RS def_lfp_Tarski));
-
-(* c : {Numb(0)} <+> A <*> List(A) ==> c : List(A) *)
-val ListI = List_unfold RS equalityD2 RS subsetD;
-
-(* NIL is a List -- this also justifies the type definition*)
-goalw List.thy [NIL_def] "NIL: List(A)";
-by (rtac (singletonI RS usum_In0I RS ListI) 1);
-val NIL_I = result();
-
-goalw List.thy [CONS_def]
-    "!!a A M. [| a: A;  M: List(A) |] ==> CONS(a,M) : List(A)";
-by (REPEAT (ares_tac [uprodI RS usum_In1I RS ListI] 1));
-val CONS_I = result();
-
 (*** Isomorphisms ***)
 
-goal List.thy "inj(Rep_List)";
+goal List.thy "inj(Rep_list)";
 by (rtac inj_inverseI 1);
-by (rtac Rep_List_inverse 1);
-val inj_Rep_List = result();
+by (rtac Rep_list_inverse 1);
+val inj_Rep_list = result();
 
-goal List.thy "inj_onto(Abs_List,List(range(Leaf)))";
+goal List.thy "inj_onto(Abs_list,list(range(Leaf)))";
 by (rtac inj_onto_inverseI 1);
-by (etac Abs_List_inverse 1);
-val inj_onto_Abs_List = result();
+by (etac Abs_list_inverse 1);
+val inj_onto_Abs_list = result();
 
 (** Distinctness of constructors **)
 
-goalw List.thy [NIL_def,CONS_def] "CONS(M,N) ~= NIL";
+goalw List.thy list_con_defs "CONS(M,N) ~= NIL";
 by (rtac In1_not_In0 1);
 val CONS_not_NIL = result();
 val NIL_not_CONS = standard (CONS_not_NIL RS not_sym);
@@ -105,8 +70,8 @@
 val NIL_neq_CONS = sym RS CONS_neq_NIL;
 
 goalw List.thy [Nil_def,Cons_def] "x # xs ~= Nil";
-by (rtac (CONS_not_NIL RS (inj_onto_Abs_List RS inj_onto_contraD)) 1);
-by (REPEAT (resolve_tac [rangeI, NIL_I, CONS_I, Rep_List] 1));
+by (rtac (CONS_not_NIL RS (inj_onto_Abs_list RS inj_onto_contraD)) 1);
+by (REPEAT (resolve_tac (list.intrs @ [rangeI, Rep_list]) 1));
 val Cons_not_Nil = result();
 
 val Nil_not_Cons = standard (Cons_not_Nil RS not_sym);
@@ -123,37 +88,37 @@
 val CONS_inject = standard (CONS_CONS_eq RS iffD1 RS conjE);
 
 (*For reasoning about abstract list constructors*)
-val List_cs = set_cs addIs [Rep_List, NIL_I, CONS_I]
+val list_cs = set_cs addIs [Rep_list] @ list.intrs
 	             addSEs [CONS_neq_NIL,NIL_neq_CONS,CONS_inject]
-		     addSDs [inj_onto_Abs_List RS inj_ontoD,
-			     inj_Rep_List RS injD, Leaf_inject];
+		     addSDs [inj_onto_Abs_list RS inj_ontoD,
+			     inj_Rep_list RS injD, Leaf_inject];
 
 goalw List.thy [Cons_def] "(x#xs=y#ys) = (x=y & xs=ys)";
-by (fast_tac List_cs 1);
+by (fast_tac list_cs 1);
 val Cons_Cons_eq = result();
 val Cons_inject = standard (Cons_Cons_eq RS iffD1 RS conjE);
 
-val [major] = goal List.thy "CONS(M,N): List(A) ==> M: A & N: List(A)";
+val [major] = goal List.thy "CONS(M,N): list(A) ==> M: A & N: list(A)";
 by (rtac (major RS setup_induction) 1);
-by (etac List_induct 1);
-by (ALLGOALS (fast_tac List_cs));
+by (etac list.induct 1);
+by (ALLGOALS (fast_tac list_cs));
 val CONS_D = result();
 
 val prems = goalw List.thy [CONS_def,In1_def]
-    "CONS(M,N): Sexp ==> M: Sexp & N: Sexp";
+    "CONS(M,N): sexp ==> M: sexp & N: sexp";
 by (cut_facts_tac prems 1);
 by (fast_tac (set_cs addSDs [Scons_D]) 1);
-val Sexp_CONS_D = result();
+val sexp_CONS_D = result();
 
 
 (*Basic ss with constructors and their freeness*)
 val list_free_simps = [Cons_not_Nil, Nil_not_Cons, Cons_Cons_eq,
-		       CONS_not_NIL, NIL_not_CONS, CONS_CONS_eq,
-		       NIL_I, CONS_I];
+		       CONS_not_NIL, NIL_not_CONS, CONS_CONS_eq]
+                      @ list.intrs;
 val list_free_ss = HOL_ss  addsimps  list_free_simps;
 
-goal List.thy "!!N. N: List(A) ==> !M. N ~= CONS(M,N)";
-by (etac List_induct 1);
+goal List.thy "!!N. N: list(A) ==> !M. N ~= CONS(M,N)";
+by (etac list.induct 1);
 by (ALLGOALS (asm_simp_tac list_free_ss));
 val not_CONS_self = result();
 
@@ -180,34 +145,35 @@
 by (simp_tac (HOL_ss addsimps [Split,Case_In1]) 1);
 val List_case_CONS = result();
 
-(*** List_rec -- by wf recursion on pred_Sexp ***)
+(*** List_rec -- by wf recursion on pred_sexp ***)
+
+(* The trancl(pred_sexp) is essential because pred_sexp_CONS_I1,2 would not
+   hold if pred_sexp^+ were changed to pred_sexp. *)
 
-(* The trancl(pred_sexp) is essential because pred_Sexp_CONS_I1,2 would not
-   hold if pred_Sexp^+ were changed to pred_Sexp. *)
+val List_rec_unfold = [List_rec_def, wf_pred_sexp RS wf_trancl] MRS def_wfrec
+                      |> standard;
 
-val List_rec_unfold = wf_pred_Sexp RS wf_trancl RS (List_rec_def RS def_wfrec);
-
-(** pred_Sexp lemmas **)
+(** pred_sexp lemmas **)
 
 goalw List.thy [CONS_def,In1_def]
-    "!!M. [| M: Sexp;  N: Sexp |] ==> <M, CONS(M,N)> : pred_Sexp^+";
-by (asm_simp_tac pred_Sexp_ss 1);
-val pred_Sexp_CONS_I1 = result();
+    "!!M. [| M: sexp;  N: sexp |] ==> <M, CONS(M,N)> : pred_sexp^+";
+by (asm_simp_tac pred_sexp_ss 1);
+val pred_sexp_CONS_I1 = result();
 
 goalw List.thy [CONS_def,In1_def]
-    "!!M. [| M: Sexp;  N: Sexp |] ==> <N, CONS(M,N)> : pred_Sexp^+";
-by (asm_simp_tac pred_Sexp_ss 1);
-val pred_Sexp_CONS_I2 = result();
+    "!!M. [| M: sexp;  N: sexp |] ==> <N, CONS(M,N)> : pred_sexp^+";
+by (asm_simp_tac pred_sexp_ss 1);
+val pred_sexp_CONS_I2 = result();
 
 val [prem] = goal List.thy
-    "<CONS(M1,M2), N> : pred_Sexp^+ ==> \
-\    <M1,N> : pred_Sexp^+ & <M2,N> : pred_Sexp^+";
-by (rtac (prem RS (pred_Sexp_subset_Sigma RS trancl_subset_Sigma RS 
+    "<CONS(M1,M2), N> : pred_sexp^+ ==> \
+\    <M1,N> : pred_sexp^+ & <M2,N> : pred_sexp^+";
+by (rtac (prem RS (pred_sexp_subset_Sigma RS trancl_subset_Sigma RS 
 		   subsetD RS SigmaE2)) 1);
-by (etac (Sexp_CONS_D RS conjE) 1);
-by (REPEAT (ares_tac [conjI, pred_Sexp_CONS_I1, pred_Sexp_CONS_I2,
+by (etac (sexp_CONS_D RS conjE) 1);
+by (REPEAT (ares_tac [conjI, pred_sexp_CONS_I1, pred_sexp_CONS_I2,
 		      prem RSN (2, trans_trancl RS transD)] 1));
-val pred_Sexp_CONS_D = result();
+val pred_sexp_CONS_D = result();
 
 (** Conversion rules for List_rec **)
 
@@ -216,24 +182,25 @@
 by (simp_tac (HOL_ss addsimps [List_case_NIL]) 1);
 val List_rec_NIL = result();
 
-goal List.thy "!!M. [| M: Sexp;  N: Sexp |] ==> \
+goal List.thy "!!M. [| M: sexp;  N: sexp |] ==> \
 \    List_rec(CONS(M,N), c, h) = h(M, N, List_rec(N,c,h))";
 by (rtac (List_rec_unfold RS trans) 1);
 by (asm_simp_tac
-    (HOL_ss addsimps [List_case_CONS, CONS_I, pred_Sexp_CONS_I2, cut_apply])1);
+    (HOL_ss addsimps [List_case_CONS, list.CONS_I, pred_sexp_CONS_I2, 
+		      cut_apply])1);
 val List_rec_CONS = result();
 
 (*** list_rec -- by List_rec ***)
 
-val Rep_List_in_Sexp =
-    [range_Leaf_subset_Sexp RS List_subset_Sexp, Rep_List] MRS subsetD;
+val Rep_list_in_sexp =
+    [range_Leaf_subset_sexp RS list_subset_sexp, Rep_list] MRS subsetD;
 
 local
   val list_rec_simps = list_free_simps @
 	          [List_rec_NIL, List_rec_CONS, 
-		   Abs_List_inverse, Rep_List_inverse,
-		   Rep_List, rangeI, inj_Leaf, Inv_f_f,
-		   Sexp_LeafI, Rep_List_in_Sexp]
+		   Abs_list_inverse, Rep_list_inverse,
+		   Rep_list, rangeI, inj_Leaf, Inv_f_f,
+		   sexp.LeafI, Rep_list_in_sexp]
 in
   val list_rec_Nil = prove_goalw List.thy [list_rec_def, Nil_def]
       "list_rec(Nil,c,h) = c"
@@ -250,16 +217,16 @@
 
 
 (*Type checking.  Useful?*)
-val major::A_subset_Sexp::prems = goal List.thy
-    "[| M: List(A);    	\
-\       A<=Sexp;      	\
+val major::A_subset_sexp::prems = goal List.thy
+    "[| M: list(A);    	\
+\       A<=sexp;      	\
 \       c: C(NIL);      \
-\       !!x y r. [| x: A;  y: List(A);  r: C(y) |] ==> h(x,y,r): C(CONS(x,y)) \
-\    |] ==> List_rec(M,c,h) : C(M :: 'a node set)";
-val Sexp_ListA_I = A_subset_Sexp RS List_subset_Sexp RS subsetD;
-val Sexp_A_I = A_subset_Sexp RS subsetD;
-by (rtac (major RS List_induct) 1);
-by (ALLGOALS(asm_simp_tac (list_ss addsimps ([Sexp_A_I,Sexp_ListA_I]@prems))));
+\       !!x y r. [| x: A;  y: list(A);  r: C(y) |] ==> h(x,y,r): C(CONS(x,y)) \
+\    |] ==> List_rec(M,c,h) : C(M :: 'a item)";
+val sexp_ListA_I = A_subset_sexp RS list_subset_sexp RS subsetD;
+val sexp_A_I = A_subset_sexp RS subsetD;
+by (rtac (major RS list.induct) 1);
+by (ALLGOALS(asm_simp_tac (list_ss addsimps ([sexp_A_I,sexp_ListA_I]@prems))));
 val List_rec_type = result();
 
 (** Generalized map functionals **)
@@ -273,7 +240,7 @@
 by (rtac list_rec_Cons 1);
 val Rep_map_Cons = result();
 
-goalw List.thy [Rep_map_def] "!!f. (!!x. f(x): A) ==> Rep_map(f,xs): List(A)";
+goalw List.thy [Rep_map_def] "!!f. (!!x. f(x): A) ==> Rep_map(f,xs): list(A)";
 by (rtac list_induct 1);
 by(ALLGOALS(asm_simp_tac list_ss));
 val Rep_map_type = result();
@@ -283,7 +250,7 @@
 val Abs_map_NIL = result();
 
 val prems = goalw List.thy [Abs_map_def]
-    "[| M: Sexp;  N: Sexp |] ==> \
+    "[| M: sexp;  N: sexp |] ==> \
 \    Abs_map(g, CONS(M,N)) = g(M) # Abs_map(g,N)";
 by (REPEAT (resolve_tac (List_rec_CONS::prems) 1));
 val Abs_map_CONS = result();
@@ -380,11 +347,11 @@
 		 map_Nil, map_Cons];
 val map_ss = list_free_ss addsimps map_simps;
 
-val [major,A_subset_Sexp,minor] = goal List.thy 
-    "[| M: List(A);  A<=Sexp;  !!z. z: A ==> f(g(z)) = z |] \
+val [major,A_subset_sexp,minor] = goal List.thy 
+    "[| M: list(A);  A<=sexp;  !!z. z: A ==> f(g(z)) = z |] \
 \    ==> Rep_map(f, Abs_map(g,M)) = M";
-by (rtac (major RS List_induct) 1);
-by (ALLGOALS (asm_simp_tac(map_ss addsimps [Sexp_A_I,Sexp_ListA_I,minor])));
+by (rtac (major RS list.induct) 1);
+by (ALLGOALS (asm_simp_tac(map_ss addsimps [sexp_A_I,sexp_ListA_I,minor])));
 val Abs_map_inverse = result();
 
 (*Rep_map_inverse is obtained via Abs_Rep_map and map_ident*)
@@ -417,11 +384,11 @@
 by (ALLGOALS (asm_simp_tac map_ss));
 val map_compose = result();
 
-goal List.thy "!!f. (!!x. f(x): Sexp) ==> \
+goal List.thy "!!f. (!!x. f(x): sexp) ==> \
 \	Abs_map(g, Rep_map(f,xs)) = map(%t. g(f(t)), xs)";
 by (list_ind_tac "xs" 1);
 by(ALLGOALS(asm_simp_tac(map_ss addsimps
-       [Rep_map_type,List_Sexp RS subsetD])));
+       [Rep_map_type,list_sexp RS subsetD])));
 val Abs_Rep_map = result();
 
 val list_ss = list_ss addsimps