enrich path , inputlist , outputlist with comment: this specification defines functions input, output that collect the inputs and outputs done on a path. The predicate Protocol is defined using these functions.; functions inputs : path → Jlist; outputs : path → Plist; predicates Protocol : V × Jlist × Plist × V; variables v' : V; axioms inputs-base : ⊦ inputs(v ') = []; used for : s, ls; inputs-rec : ⊦ inputs(mkpa(v, j, p, pa)) = j + inputs(pa); used for : s, ls; outputs-base : ⊦ outputs(v ') = []; used for : s, ls; outputs-rec : ⊦ outputs(mkpa(v, j, p, pa)) = p + outputs(pa); used for : s, ls; Protocol-def : ⊦ Protocol(v, js, ps, v') ↔ (∃ pa. MPath(pa) ∧ inputs(pa) = js ∧ outputs(pa) = ps); end enrich