NO Problem 1: (VAR v_NonEmpty:S M:S N:S X:S) (RULES and(tt) -> X:S plus(N:S,0) -> N:S plus(N:S,s(M:S)) -> s(plus(N:S,M:S)) x(N:S,0) -> 0 x(N:S,s(M:S)) -> plus(x(N:S,M:S),N:S) ) Problem 1: Extra Variables Processor: -> Rules: and(tt) -> X:S plus(N:S,0) -> N:S plus(N:S,s(M:S)) -> s(plus(N:S,M:S)) x(N:S,0) -> 0 x(N:S,s(M:S)) -> plus(x(N:S,M:S),N:S) -> The system has extra variables. The problem is infinite.