(* $Id$ *)
(* call_sim_tac invokes oracle "Sim" *)
fun call_sim_tac thm_list i state =
let val sign = #sign (rep_thm state);
val (subgoal::_) = Library.drop(i-1,prems_of state);
val OraAss = sim_oracle sign (subgoal,thm_list);
in cut_facts_tac [OraAss] i state end;
val ioa_implements_def = thm "ioa_implements_def";
(* is_sim_tac makes additionally to call_sim_tac some simplifications,
which are suitable for implementation realtion formulas *)
fun is_sim_tac thm_list = SUBGOAL (fn (goal, i) =>
EVERY [REPEAT (etac thin_rl i),
simp_tac (simpset() addsimps [ioa_implements_def]) i,
rtac conjI i,
rtac conjI (i+1),
TRY(call_sim_tac thm_list (i+2)),
TRY(atac (i+2)),
REPEAT(rtac refl (i+2)),
simp_tac (simpset() addsimps (thm_list @
comp_simps @ restrict_simps @ hide_simps @
rename_simps @ ioa_simps @ asig_simps)) (i+1),
simp_tac (simpset() addsimps (thm_list @
comp_simps @ restrict_simps @ hide_simps @
rename_simps @ ioa_simps @ asig_simps)) (i)]);