enrich Atomic , Protocol , no-deadlocked-or-infinite-paths with comment: This specification defines the past and future oriented simulation relations RP and RF. The 'big step' proof obligations is given as an axiom. Proposition 3.3 and Theorem 3.4 are proved.; predicates R : U × V; RP : U × V; RF : U × V; Input : I × Jlist; Output : O × Plist; axioms big-step-ax : ⊦ Protocol(v, js, ps, v') → (∃ u, i, o, u'. R(u, v) ∧ Input(i, js) ∧ Atomic(u, i, o, u') ∧ Output(o, ps) ∧ R(u', v')); functional-R : ⊦ R(u, v) ∧ R(u', v) → u = u'; used for : f, lf; RP-def : ⊦ RP(u, v) ↔ (∃ pa. R(u, pa .first) ∧ FPath(pa) ∧ pa .last = v); RF-def : ⊦ RF(u, v) ↔ (∃ pa. pa .first = v ∧ BPath(pa) ∧ R(u, pa .last)); end enrich