| weakbwsim(IOAut(cstart, cstep, cext), IOAut(astart, astep, aext), t, aINV) ⊦ bwsim (IOAut(cstart, cstep, cext), IOAut(astart, astep, aext), t, λ cs. ∃ csl, cal. exec*(IOAut(cstart, cstep, cext))(csl, cal) ∧ csl.last = cs, λ as. aINV(as) ∧ (∃ asl, aal. exec*(IOAut(astart, astep, aext))(asl, aal) ∧ asl.last = as)) |