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