type_synonym
locals = "vname ⇀ val"―‹local vars, incl. params and ``this''› type_synonym
state = "heap × locals × sheap"
definition hp :: "state → heap" where "hp ≡ fst" definition lcl :: "state → locals" where "lcl ≡ fst ∘ snd" definition shp :: "state → sheap" where "shp ≡ snd ∘ snd"