YES We show the termination of the TRS R: a__nats() -> cons(|0|(),incr(nats())) a__pairs() -> cons(|0|(),incr(odds())) a__odds() -> a__incr(a__pairs()) a__incr(cons(X,XS)) -> cons(s(mark(X)),incr(XS)) a__head(cons(X,XS)) -> mark(X) a__tail(cons(X,XS)) -> mark(XS) mark(nats()) -> a__nats() mark(incr(X)) -> a__incr(mark(X)) mark(pairs()) -> a__pairs() mark(odds()) -> a__odds() mark(head(X)) -> a__head(mark(X)) mark(tail(X)) -> a__tail(mark(X)) mark(cons(X1,X2)) -> cons(mark(X1),X2) mark(|0|()) -> |0|() mark(s(X)) -> s(mark(X)) a__nats() -> nats() a__incr(X) -> incr(X) a__pairs() -> pairs() a__odds() -> odds() a__head(X) -> head(X) a__tail(X) -> tail(X) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__odds#() -> a__incr#(a__pairs()) p2: a__odds#() -> a__pairs#() p3: a__incr#(cons(X,XS)) -> mark#(X) p4: a__head#(cons(X,XS)) -> mark#(X) p5: a__tail#(cons(X,XS)) -> mark#(XS) p6: mark#(nats()) -> a__nats#() p7: mark#(incr(X)) -> a__incr#(mark(X)) p8: mark#(incr(X)) -> mark#(X) p9: mark#(pairs()) -> a__pairs#() p10: mark#(odds()) -> a__odds#() p11: mark#(head(X)) -> a__head#(mark(X)) p12: mark#(head(X)) -> mark#(X) p13: mark#(tail(X)) -> a__tail#(mark(X)) p14: mark#(tail(X)) -> mark#(X) p15: mark#(cons(X1,X2)) -> mark#(X1) p16: mark#(s(X)) -> mark#(X) and R consists of: r1: a__nats() -> cons(|0|(),incr(nats())) r2: a__pairs() -> cons(|0|(),incr(odds())) r3: a__odds() -> a__incr(a__pairs()) r4: a__incr(cons(X,XS)) -> cons(s(mark(X)),incr(XS)) r5: a__head(cons(X,XS)) -> mark(X) r6: a__tail(cons(X,XS)) -> mark(XS) r7: mark(nats()) -> a__nats() r8: mark(incr(X)) -> a__incr(mark(X)) r9: mark(pairs()) -> a__pairs() r10: mark(odds()) -> a__odds() r11: mark(head(X)) -> a__head(mark(X)) r12: mark(tail(X)) -> a__tail(mark(X)) r13: mark(cons(X1,X2)) -> cons(mark(X1),X2) r14: mark(|0|()) -> |0|() r15: mark(s(X)) -> s(mark(X)) r16: a__nats() -> nats() r17: a__incr(X) -> incr(X) r18: a__pairs() -> pairs() r19: a__odds() -> odds() r20: a__head(X) -> head(X) r21: a__tail(X) -> tail(X) The estimated dependency graph contains the following SCCs: {p1, p3, p4, p5, p7, p8, p10, p11, p12, p13, p14, p15, p16} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a__odds#() -> a__incr#(a__pairs()) p2: a__incr#(cons(X,XS)) -> mark#(X) p3: mark#(s(X)) -> mark#(X) p4: mark#(cons(X1,X2)) -> mark#(X1) p5: mark#(tail(X)) -> mark#(X) p6: mark#(tail(X)) -> a__tail#(mark(X)) p7: a__tail#(cons(X,XS)) -> mark#(XS) p8: mark#(head(X)) -> mark#(X) p9: mark#(head(X)) -> a__head#(mark(X)) p10: a__head#(cons(X,XS)) -> mark#(X) p11: mark#(odds()) -> a__odds#() p12: mark#(incr(X)) -> mark#(X) p13: mark#(incr(X)) -> a__incr#(mark(X)) and R consists of: r1: a__nats() -> cons(|0|(),incr(nats())) r2: a__pairs() -> cons(|0|(),incr(odds())) r3: a__odds() -> a__incr(a__pairs()) r4: a__incr(cons(X,XS)) -> cons(s(mark(X)),incr(XS)) r5: a__head(cons(X,XS)) -> mark(X) r6: a__tail(cons(X,XS)) -> mark(XS) r7: mark(nats()) -> a__nats() r8: mark(incr(X)) -> a__incr(mark(X)) r9: mark(pairs()) -> a__pairs() r10: mark(odds()) -> a__odds() r11: mark(head(X)) -> a__head(mark(X)) r12: mark(tail(X)) -> a__tail(mark(X)) r13: mark(cons(X1,X2)) -> cons(mark(X1),X2) r14: mark(|0|()) -> |0|() r15: mark(s(X)) -> s(mark(X)) r16: a__nats() -> nats() r17: a__incr(X) -> incr(X) r18: a__pairs() -> pairs() r19: a__odds() -> odds() r20: a__head(X) -> head(X) r21: a__tail(X) -> tail(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19, r20, r21 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a__odds#_A() = (1,18) a__incr#_A(x1) = x1 + (0,7) a__pairs_A() = (1,10) cons_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (0,8) mark#_A(x1) = x1 + (0,9) s_A(x1) = x1 + (0,4) tail_A(x1) = ((1,0),(1,0)) x1 + (2,1) a__tail#_A(x1) = x1 + (1,7) mark_A(x1) = x1 + (0,3) head_A(x1) = ((1,0),(1,0)) x1 + (2,2) a__head#_A(x1) = ((1,0),(0,0)) x1 + (1,10) odds_A() = (1,19) incr_A(x1) = x1 + (0,10) a__nats_A() = (1,10) |0|_A() = (0,1) nats_A() = (1,8) a__odds_A() = (1,21) a__incr_A(x1) = x1 + (0,10) a__head_A(x1) = ((1,0),(1,0)) x1 + (2,3) a__tail_A(x1) = ((1,0),(1,0)) x1 + (2,2) pairs_A() = (1,8) precedence: mark = a__head > a__pairs > a__tail > a__incr > a__nats > head > cons > tail > a__tail# > a__head# > nats > s = a__odds > a__odds# = a__incr# = mark# = odds = incr > pairs > |0| partial status: pi(a__odds#) = [] pi(a__incr#) = [] pi(a__pairs) = [] pi(cons) = [1] pi(mark#) = [1] pi(s) = [1] pi(tail) = [] pi(a__tail#) = [1] pi(mark) = [] pi(head) = [] pi(a__head#) = [] pi(odds) = [] pi(incr) = [1] pi(a__nats) = [] pi(|0|) = [] pi(nats) = [] pi(a__odds) = [] pi(a__incr) = [1] pi(a__head) = [] pi(a__tail) = [] pi(pairs) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a__odds#_A() = (26,28) a__incr#_A(x1) = (13,27) a__pairs_A() = (9,12) cons_A(x1,x2) = x1 + (2,11) mark#_A(x1) = ((1,0),(1,1)) x1 + (3,4) s_A(x1) = ((0,0),(1,0)) x1 + (1,1) tail_A(x1) = (0,0) a__tail#_A(x1) = ((0,0),(1,0)) x1 + (1,1) mark_A(x1) = (9,28) head_A(x1) = (5,6) a__head#_A(x1) = (4,5) odds_A() = (25,0) incr_A(x1) = x1 + (10,13) a__nats_A() = (9,27) |0|_A() = (7,0) nats_A() = (0,0) a__odds_A() = (26,1) a__incr_A(x1) = (11,29) a__head_A(x1) = (9,28) a__tail_A(x1) = (10,1) pairs_A() = (1,0) precedence: a__pairs = a__odds = a__head = pairs > tail > |0| > a__nats > a__odds# = s = incr = a__incr > a__head# > a__incr# = cons = mark# = mark = a__tail > odds > head > nats > a__tail# partial status: pi(a__odds#) = [] pi(a__incr#) = [] pi(a__pairs) = [] pi(cons) = [1] pi(mark#) = [1] pi(s) = [] pi(tail) = [] pi(a__tail#) = [] pi(mark) = [] pi(head) = [] pi(a__head#) = [] pi(odds) = [] pi(incr) = [] pi(a__nats) = [] pi(|0|) = [] pi(nats) = [] pi(a__odds) = [] pi(a__incr) = [] pi(a__head) = [] pi(a__tail) = [] pi(pairs) = [] The next rules are strictly ordered: p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: mark#(incr(X)) -> a__incr#(mark(X)) and R consists of: r1: a__nats() -> cons(|0|(),incr(nats())) r2: a__pairs() -> cons(|0|(),incr(odds())) r3: a__odds() -> a__incr(a__pairs()) r4: a__incr(cons(X,XS)) -> cons(s(mark(X)),incr(XS)) r5: a__head(cons(X,XS)) -> mark(X) r6: a__tail(cons(X,XS)) -> mark(XS) r7: mark(nats()) -> a__nats() r8: mark(incr(X)) -> a__incr(mark(X)) r9: mark(pairs()) -> a__pairs() r10: mark(odds()) -> a__odds() r11: mark(head(X)) -> a__head(mark(X)) r12: mark(tail(X)) -> a__tail(mark(X)) r13: mark(cons(X1,X2)) -> cons(mark(X1),X2) r14: mark(|0|()) -> |0|() r15: mark(s(X)) -> s(mark(X)) r16: a__nats() -> nats() r17: a__incr(X) -> incr(X) r18: a__pairs() -> pairs() r19: a__odds() -> odds() r20: a__head(X) -> head(X) r21: a__tail(X) -> tail(X) The estimated dependency graph contains the following SCCs: (no SCCs)