YES We show the termination of the relative TRS R/S: R: not(true()) -> false() not(false()) -> true() evenodd(x,|0|()) -> not(evenodd(x,s(|0|()))) evenodd(|0|(),s(|0|())) -> false() evenodd(s(x),s(|0|())) -> evenodd(x,|0|()) S: rand(x) -> x rand(x) -> rand(s(x)) -- SCC decomposition. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: evenodd#(x,|0|()) -> not#(evenodd(x,s(|0|()))) p2: evenodd#(x,|0|()) -> evenodd#(x,s(|0|())) p3: evenodd#(s(x),s(|0|())) -> evenodd#(x,|0|()) and R consists of: r1: not(true()) -> false() r2: not(false()) -> true() r3: evenodd(x,|0|()) -> not(evenodd(x,s(|0|()))) r4: evenodd(|0|(),s(|0|())) -> false() r5: evenodd(s(x),s(|0|())) -> evenodd(x,|0|()) r6: rand(x) -> x r7: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: {p2, p3} -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: evenodd#(x,|0|()) -> evenodd#(x,s(|0|())) p2: evenodd#(s(x),s(|0|())) -> evenodd#(x,|0|()) and R consists of: r1: not(true()) -> false() r2: not(false()) -> true() r3: evenodd(x,|0|()) -> not(evenodd(x,s(|0|()))) r4: evenodd(|0|(),s(|0|())) -> false() r5: evenodd(s(x),s(|0|())) -> evenodd(x,|0|()) r6: rand(x) -> x r7: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^4 order: lexicographic order interpretations: evenodd#_A(x1,x2) = ((1,0,0,0),(0,0,0,0),(0,1,0,0),(0,1,1,0)) x1 + ((0,0,0,0),(0,0,0,0),(0,0,0,0),(1,0,0,0)) x2 |0|_A() = (1,0,2,1) s_A(x1) = ((1,0,0,0),(0,1,0,0),(1,0,0,0),(1,0,0,0)) x1 + (0,1,1,1) not_A(x1) = x1 + (0,2,2,3) true_A() = (1,1,1,0) false_A() = (1,1,1,0) evenodd_A(x1,x2) = ((1,0,0,0),(0,1,0,0),(0,0,0,0),(0,0,1,0)) x2 + (1,3,3,0) rand_A(x1) = x1 + (1,1,1,1) 2. lexicographic path order with precedence: precedence: rand > evenodd > evenodd# > not > s > |0| > false > true argument filter: pi(evenodd#) = [] pi(|0|) = [] pi(s) = [] pi(not) = [] pi(true) = [] pi(false) = [] pi(evenodd) = [] pi(rand) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: evenodd#(x,|0|()) -> evenodd#(x,s(|0|())) and R consists of: r1: not(true()) -> false() r2: not(false()) -> true() r3: evenodd(x,|0|()) -> not(evenodd(x,s(|0|()))) r4: evenodd(|0|(),s(|0|())) -> false() r5: evenodd(s(x),s(|0|())) -> evenodd(x,|0|()) r6: rand(x) -> x r7: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: (no SCCs)