MAYBE Problem: f(tt(),x) -> f(isNat(x),s(x)) isNat(s(x)) -> isNat(x) isNat(0()) -> tt() Proof: DP Processor: DPs: f#(tt(),x) -> isNat#(x) f#(tt(),x) -> f#(isNat(x),s(x)) isNat#(s(x)) -> isNat#(x) TRS: f(tt(),x) -> f(isNat(x),s(x)) isNat(s(x)) -> isNat(x) isNat(0()) -> tt() Open