src/HOLCF/Lift3.ML

Added "discrete" CPOs and modified IMP to use those rather than "lift"

(*  Title:      HOLCF/Lift3.ML
    ID:         $Id$
    Author:     Olaf Mueller, Robert Sandner
    Copyright   1996 Technische Universitaet Muenchen

Theorems for Lift3.thy
*)


(* for compatibility with old HOLCF-Version *)
qed_goal "inst_lift_pcpo" thy "UU = Undef"
 (fn prems => 
        [
        (simp_tac (HOL_ss addsimps [UU_def,UU_lift_def]) 1)
        ]);

(* ----------------------------------------------------------- *)
(*                        From Undef to UU		       *)
(* ----------------------------------------------------------- *)

Addsimps [inst_lift_pcpo];

local

val case1' = prove_goal Lift3.thy "lift_case f1 f2 UU = f1"
	     (fn _ => [simp_tac (!simpset addsimps lift.simps) 1]);

val case2' = prove_goal Lift3.thy "lift_case f1 f2 (Def a) = f2 a"
	     (fn _ => [Simp_tac 1]);

val distinct1' = prove_goal Lift3.thy "UU ~= Def a" 
		 (fn _ => [Simp_tac 1]);

val distinct2' = prove_goal Lift3.thy "Def a ~= UU"
		 (fn _ => [Simp_tac 1]);

val inject' = prove_goal Lift3.thy "Def a = Def aa = (a = aa)"
	       (fn _ => [Simp_tac 1]);

val rec1' = prove_goal Lift3.thy "lift_rec f1 f2 UU = f1"
	    (fn _ => [Simp_tac 1]);

val rec2' = prove_goal Lift3.thy "lift_rec f1 f2 (Def a) = f2 a"
	    (fn _ => [Simp_tac 1]);

val induct' = prove_goal Lift3.thy "[| P UU; !a. P (Def a) |] ==> P lift"
	    (fn prems => [cut_facts_tac prems 1, Asm_full_simp_tac 1,
		      etac Lift1.lift.induct 1,fast_tac HOL_cs 1]);

in 

val Def_not_UU = distinct1' RS not_sym;

structure lift =
struct
val cases = [case1',case2'];
val distinct = [distinct1',distinct2'];
val inject = [inject'];
val induct = allI RSN(2,induct');
val recs = [rec1',rec2'];
val simps = cases@distinct@inject@recs;
fun induct_tac (s:string) (i:int) = 
    (res_inst_tac [("lift",s)] induct i);
end;

end; (* local *)

Delsimps [inst_lift_pcpo];
Delsimps lift.simps;

Addsimps [inst_lift_pcpo RS sym];
Addsimps lift.simps;


(* -------------------------------------------------------------------------*)
(* rewrite_rule for less_lift 						    *)
(* -------------------------------------------------------------------------*)

goal Lift3.thy "(x::'a lift) << y = (x=y | x=UU)";
br (inst_lift_po RS ssubst) 1;
by (Simp_tac 1);
val less_lift = result();




(* ---------------------------------------------------------- *)
(*                  Relating UU and Undef                     *)
(* ---------------------------------------------------------- *)

goal Lift3.thy "x=UU | (? y.x=Def y)"; 
by (lift.induct_tac "x" 1);
by (Asm_simp_tac 1);
by (rtac disjI2 1);
by (rtac exI 1);
by (Asm_simp_tac 1);
qed"Lift_exhaust";

val prems = goal Lift3.thy 
  "[| x = UU ==> P; ? a. x = Def a ==> P |] ==> P";
by (cut_facts_tac [Lift_exhaust] 1);
by (fast_tac (HOL_cs addSEs prems) 1);
qed"Lift_cases";

goal thy
  "P(lift_case a b x) = ((x=UU --> P a) & (!y. x = Def y --> P(b y)))";
by(lift.induct_tac "x" 1);
by(ALLGOALS Asm_simp_tac);
qed "expand_lift_case";

goal Lift3.thy "(x~=UU)=(? y.x=Def y)";
br iffI 1;
 br Lift_cases 1;
  by (fast_tac HOL_cs 1);
 by (fast_tac HOL_cs 1);
by (fast_tac (HOL_cs addSIs lift.distinct) 1);
qed"not_Undef_is_Def";

val Undef_eq_UU = inst_lift_pcpo RS sym;

val DefE = prove_goal Lift3.thy "Def x = UU ==> R" 
    (fn prems => [
        cut_facts_tac prems 1,
        asm_full_simp_tac (HOL_ss addsimps [Def_not_UU]) 1]);

val prems = goal Lift3.thy "[| x = Def s; x = UU |] ==> R";
by (cut_facts_tac prems 1);
by (fast_tac (HOL_cs addSDs [DefE]) 1);
val DefE2 = result();

(* ---------------------------------------------------------- *)
(*                          Lift is flat                     *)
(* ---------------------------------------------------------- *)

goalw Lift3.thy [flat_def] "flat (x::'a lift)";
by (simp_tac (!simpset addsimps [less_lift]) 1);
val flat_lift = result();

bind_thm("ax_flat_lift",flat_lift RS flatE);


(* ---------------------------------------------------------- *)
(*       More Continuity Proofs and Extended Tactic           *)
(* ---------------------------------------------------------- *)

goal Lift3.thy "cont (%x. case x of Undef => UU | Def a => f a)";

br flatdom_strict2cont 1;
 br flat_lift 1;
by (Simp_tac 1);

val cont_flift1_arg = result();



goal Lift3.thy "cont (%x. case x of Undef => UU | Def a => Def (f a))";

br flatdom_strict2cont 1;
 br flat_lift 1;
by (Simp_tac 1);

val cont_flift2_arg = result();



goal Lift3.thy "!!f. [|! a.cont (%y. (f y) a)|] ==> \
\   cont (%y. case x of Undef => UU | Def a => (f y) a)";

by (res_inst_tac [("x","x")] Lift_cases 1);
 by (Asm_simp_tac 1);
by (fast_tac (HOL_cs addss !simpset) 1);

qed"cont_flift1_not_arg";

val cont_flift1_not_arg2 = (allI RS cont_flift1_not_arg);




(* zusammenfassen zu cont(%y. ((f y)`(g y)) s)     *)

goal Lift3.thy "!!f.cont g ==> cont(%x. (f`(g x)) s)";
by (rtac monocontlub2cont 1);
(* monotone *)
 by (rtac monofunI 1);
 by (strip_tac 1);
 by (rtac (monofun_cfun_arg RS monofun_fun_fun) 1);
 by (etac (cont2mono RS monofunE RS spec RS spec RS mp) 1); 
 by (atac 1);
(* contlub *)
by (rtac contlubI 1);
by (strip_tac 1);
by ((rtac (cont2contlub RS contlubE RS spec RS mp RS ssubst) 1) THEN (atac 1));
 ba 1;
by (stac (contlub_cfun_arg RS fun_cong) 1);
 be (cont2mono RS ch2ch_monofun) 1;
 ba 1;
by (stac thelub_fun 1);
 by (fast_tac ((HOL_cs addSIs [ch2ch_fappR]) 
		       addSEs [cont2mono RS ch2ch_monofun]) 1);
br refl 1;
qed"cont_fapp_app1";


goal Lift3.thy "cont(%y. (y`x) s)";
by (rtac monocontlub2cont 1);
 (* monotone *)
 by (rtac monofunI 1);
 by (strip_tac 1); 
 be (monofun_cfun_fun RS monofun_fun_fun) 1;
(* continuous *)
by (rtac contlubI 1);
by (strip_tac 1);
by (stac (contlub_cfun_fun RS fun_cong) 1);
 by (atac 1);
by (stac thelub_fun 1);
 be ch2ch_fappL 1;
br refl 1;
qed"cont_fapp_app2";



val prems = goal Lift3.thy "[| cont f1; cont f2 |] ==> \
\   cont (%x. if b then f1 x else f2 x)";

by (cut_facts_tac prems 1);
by (case_tac "b" 1);
by (TRYALL (fast_tac (HOL_cs addss HOL_ss)));

val cont_if = result();



val cont2cont_CF1L_rev2 = (allI RS cont2cont_CF1L_rev);

val cont_lemmas2 =  cont_lemmas1@
		   [cont_flift1_arg,cont_flift2_arg,
                    cont_flift1_not_arg2,cont2cont_CF1L_rev2, 
                    cont_fapp_app1,cont_fapp_app2,cont_if];

Addsimps 	   [cont_flift1_arg,cont_flift2_arg,
                    cont_flift1_not_arg2,cont2cont_CF1L_rev2, 
                    cont_fapp_app1,cont_fapp_app2,cont_if];

fun cont_tac  i = resolve_tac cont_lemmas2 i;
fun cont_tacR i = simp_tac (!simpset addsimps [flift1_def,flift2_def]) i THEN
		  REPEAT (cont_tac i);

simpset := !simpset addSolver (K (DEPTH_SOLVE_1 o cont_tac));