Theory Interp

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(* Project: The Isabelle/UTP Proof System                                     *)
(* File: Interp.thy                                                           *)
(* Authors: Simon Foster and Frank Zeyda                                      *)
(* Emails: simon.foster@york.ac.uk frank.zeyda@york.ac.uk                     *)
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(* LAST REVIEWED: 7/12/2016 *)

section ‹Interpretation Tools›

theory Interp
imports Main
begin

subsection ‹Interpretation Locale›

locale interp =
fixes f :: "'a ⇒ 'b"
assumes f_inj : "inj f"
begin
lemma meta_interp_law:
"(⋀P. PROP Q P) ≡ (⋀P. PROP Q (P o f))"
  apply (rule equal_intr_rule)
    ― ‹Subgoal 1›
   apply (drule_tac x = "P o f" in meta_spec)
   apply (assumption)
    ― ‹Subgoal 2›
  apply (drule_tac x = "P o inv f" in meta_spec)
  apply (simp add: f_inj)
done

lemma all_interp_law:
"(∀P. Q P) = (∀P. Q (P o f))"
  apply (safe)
    ― ‹Subgoal 1›
   apply (drule_tac x = "P o f" in spec)
   apply (assumption)
    ― ‹Subgoal 2›
  apply (drule_tac x = "P o inv f" in spec)
  apply (simp add: f_inj)
done

lemma exists_interp_law:
"(∃P. Q P) = (∃P. Q (P o f))"
  apply (safe)
    ― ‹Subgoal 1›
   apply (rule_tac x = "P o inv f" in exI)
   apply (simp add: f_inj)
    ― ‹Subgoal 2›
  apply (rule_tac x = "P o f" in exI)
  apply (assumption)
done
end
end