/export/starexec/sandbox2/solver/bin/starexec_run_standard /export/starexec/sandbox2/benchmark/theBenchmark.xml /export/starexec/sandbox2/output/output_files -------------------------------------------------------------------------------- YES proof of /export/starexec/sandbox2/benchmark/theBenchmark.xml # AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty Termination w.r.t. Q of the given QTRS could be proven: (0) QTRS (1) QTRSToCSRProof [EQUIVALENT, 0 ms] (2) CSR (3) CSRInnermostProof [EQUIVALENT, 0 ms] (4) CSR (5) CSDependencyPairsProof [EQUIVALENT, 0 ms] (6) QCSDP (7) QCSDependencyGraphProof [EQUIVALENT, 0 ms] (8) AND (9) QCSDP (10) QCSDPSubtermProof [EQUIVALENT, 0 ms] (11) QCSDP (12) PIsEmptyProof [EQUIVALENT, 0 ms] (13) YES (14) QCSDP (15) QCSDPSubtermProof [EQUIVALENT, 0 ms] (16) QCSDP (17) QCSDependencyGraphProof [EQUIVALENT, 0 ms] (18) TRUE ---------------------------------------- (0) Obligation: Q restricted rewrite system: The TRS R consists of the following rules: active(U11(tt, N, X, XS)) -> mark(U12(splitAt(N, XS), X)) active(U12(pair(YS, ZS), X)) -> mark(pair(cons(X, YS), ZS)) active(afterNth(N, XS)) -> mark(snd(splitAt(N, XS))) active(and(tt, X)) -> mark(X) active(fst(pair(X, Y))) -> mark(X) active(head(cons(N, XS))) -> mark(N) active(natsFrom(N)) -> mark(cons(N, natsFrom(s(N)))) active(sel(N, XS)) -> mark(head(afterNth(N, XS))) active(snd(pair(X, Y))) -> mark(Y) active(splitAt(0, XS)) -> mark(pair(nil, XS)) active(splitAt(s(N), cons(X, XS))) -> mark(U11(tt, N, X, XS)) active(tail(cons(N, XS))) -> mark(XS) active(take(N, XS)) -> mark(fst(splitAt(N, XS))) active(U11(X1, X2, X3, X4)) -> U11(active(X1), X2, X3, X4) active(U12(X1, X2)) -> U12(active(X1), X2) active(splitAt(X1, X2)) -> splitAt(active(X1), X2) active(splitAt(X1, X2)) -> splitAt(X1, active(X2)) active(pair(X1, X2)) -> pair(active(X1), X2) active(pair(X1, X2)) -> pair(X1, active(X2)) active(cons(X1, X2)) -> cons(active(X1), X2) active(afterNth(X1, X2)) -> afterNth(active(X1), X2) active(afterNth(X1, X2)) -> afterNth(X1, active(X2)) active(snd(X)) -> snd(active(X)) active(and(X1, X2)) -> and(active(X1), X2) active(fst(X)) -> fst(active(X)) active(head(X)) -> head(active(X)) active(natsFrom(X)) -> natsFrom(active(X)) active(s(X)) -> s(active(X)) active(sel(X1, X2)) -> sel(active(X1), X2) active(sel(X1, X2)) -> sel(X1, active(X2)) active(tail(X)) -> tail(active(X)) active(take(X1, X2)) -> take(active(X1), X2) active(take(X1, X2)) -> take(X1, active(X2)) U11(mark(X1), X2, X3, X4) -> mark(U11(X1, X2, X3, X4)) U12(mark(X1), X2) -> mark(U12(X1, X2)) splitAt(mark(X1), X2) -> mark(splitAt(X1, X2)) splitAt(X1, mark(X2)) -> mark(splitAt(X1, X2)) pair(mark(X1), X2) -> mark(pair(X1, X2)) pair(X1, mark(X2)) -> mark(pair(X1, X2)) cons(mark(X1), X2) -> mark(cons(X1, X2)) afterNth(mark(X1), X2) -> mark(afterNth(X1, X2)) afterNth(X1, mark(X2)) -> mark(afterNth(X1, X2)) snd(mark(X)) -> mark(snd(X)) and(mark(X1), X2) -> mark(and(X1, X2)) fst(mark(X)) -> mark(fst(X)) head(mark(X)) -> mark(head(X)) natsFrom(mark(X)) -> mark(natsFrom(X)) s(mark(X)) -> mark(s(X)) sel(mark(X1), X2) -> mark(sel(X1, X2)) sel(X1, mark(X2)) -> mark(sel(X1, X2)) tail(mark(X)) -> mark(tail(X)) take(mark(X1), X2) -> mark(take(X1, X2)) take(X1, mark(X2)) -> mark(take(X1, X2)) proper(U11(X1, X2, X3, X4)) -> U11(proper(X1), proper(X2), proper(X3), proper(X4)) proper(tt) -> ok(tt) proper(U12(X1, X2)) -> U12(proper(X1), proper(X2)) proper(splitAt(X1, X2)) -> splitAt(proper(X1), proper(X2)) proper(pair(X1, X2)) -> pair(proper(X1), proper(X2)) proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)) proper(afterNth(X1, X2)) -> afterNth(proper(X1), proper(X2)) proper(snd(X)) -> snd(proper(X)) proper(and(X1, X2)) -> and(proper(X1), proper(X2)) proper(fst(X)) -> fst(proper(X)) proper(head(X)) -> head(proper(X)) proper(natsFrom(X)) -> natsFrom(proper(X)) proper(s(X)) -> s(proper(X)) proper(sel(X1, X2)) -> sel(proper(X1), proper(X2)) proper(0) -> ok(0) proper(nil) -> ok(nil) proper(tail(X)) -> tail(proper(X)) proper(take(X1, X2)) -> take(proper(X1), proper(X2)) U11(ok(X1), ok(X2), ok(X3), ok(X4)) -> ok(U11(X1, X2, X3, X4)) U12(ok(X1), ok(X2)) -> ok(U12(X1, X2)) splitAt(ok(X1), ok(X2)) -> ok(splitAt(X1, X2)) pair(ok(X1), ok(X2)) -> ok(pair(X1, X2)) cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)) afterNth(ok(X1), ok(X2)) -> ok(afterNth(X1, X2)) snd(ok(X)) -> ok(snd(X)) and(ok(X1), ok(X2)) -> ok(and(X1, X2)) fst(ok(X)) -> ok(fst(X)) head(ok(X)) -> ok(head(X)) natsFrom(ok(X)) -> ok(natsFrom(X)) s(ok(X)) -> ok(s(X)) sel(ok(X1), ok(X2)) -> ok(sel(X1, X2)) tail(ok(X)) -> ok(tail(X)) take(ok(X1), ok(X2)) -> ok(take(X1, X2)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Q is empty. ---------------------------------------- (1) QTRSToCSRProof (EQUIVALENT) The following Q TRS is given: Q restricted rewrite system: The TRS R consists of the following rules: active(U11(tt, N, X, XS)) -> mark(U12(splitAt(N, XS), X)) active(U12(pair(YS, ZS), X)) -> mark(pair(cons(X, YS), ZS)) active(afterNth(N, XS)) -> mark(snd(splitAt(N, XS))) active(and(tt, X)) -> mark(X) active(fst(pair(X, Y))) -> mark(X) active(head(cons(N, XS))) -> mark(N) active(natsFrom(N)) -> mark(cons(N, natsFrom(s(N)))) active(sel(N, XS)) -> mark(head(afterNth(N, XS))) active(snd(pair(X, Y))) -> mark(Y) active(splitAt(0, XS)) -> mark(pair(nil, XS)) active(splitAt(s(N), cons(X, XS))) -> mark(U11(tt, N, X, XS)) active(tail(cons(N, XS))) -> mark(XS) active(take(N, XS)) -> mark(fst(splitAt(N, XS))) active(U11(X1, X2, X3, X4)) -> U11(active(X1), X2, X3, X4) active(U12(X1, X2)) -> U12(active(X1), X2) active(splitAt(X1, X2)) -> splitAt(active(X1), X2) active(splitAt(X1, X2)) -> splitAt(X1, active(X2)) active(pair(X1, X2)) -> pair(active(X1), X2) active(pair(X1, X2)) -> pair(X1, active(X2)) active(cons(X1, X2)) -> cons(active(X1), X2) active(afterNth(X1, X2)) -> afterNth(active(X1), X2) active(afterNth(X1, X2)) -> afterNth(X1, active(X2)) active(snd(X)) -> snd(active(X)) active(and(X1, X2)) -> and(active(X1), X2) active(fst(X)) -> fst(active(X)) active(head(X)) -> head(active(X)) active(natsFrom(X)) -> natsFrom(active(X)) active(s(X)) -> s(active(X)) active(sel(X1, X2)) -> sel(active(X1), X2) active(sel(X1, X2)) -> sel(X1, active(X2)) active(tail(X)) -> tail(active(X)) active(take(X1, X2)) -> take(active(X1), X2) active(take(X1, X2)) -> take(X1, active(X2)) U11(mark(X1), X2, X3, X4) -> mark(U11(X1, X2, X3, X4)) U12(mark(X1), X2) -> mark(U12(X1, X2)) splitAt(mark(X1), X2) -> mark(splitAt(X1, X2)) splitAt(X1, mark(X2)) -> mark(splitAt(X1, X2)) pair(mark(X1), X2) -> mark(pair(X1, X2)) pair(X1, mark(X2)) -> mark(pair(X1, X2)) cons(mark(X1), X2) -> mark(cons(X1, X2)) afterNth(mark(X1), X2) -> mark(afterNth(X1, X2)) afterNth(X1, mark(X2)) -> mark(afterNth(X1, X2)) snd(mark(X)) -> mark(snd(X)) and(mark(X1), X2) -> mark(and(X1, X2)) fst(mark(X)) -> mark(fst(X)) head(mark(X)) -> mark(head(X)) natsFrom(mark(X)) -> mark(natsFrom(X)) s(mark(X)) -> mark(s(X)) sel(mark(X1), X2) -> mark(sel(X1, X2)) sel(X1, mark(X2)) -> mark(sel(X1, X2)) tail(mark(X)) -> mark(tail(X)) take(mark(X1), X2) -> mark(take(X1, X2)) take(X1, mark(X2)) -> mark(take(X1, X2)) proper(U11(X1, X2, X3, X4)) -> U11(proper(X1), proper(X2), proper(X3), proper(X4)) proper(tt) -> ok(tt) proper(U12(X1, X2)) -> U12(proper(X1), proper(X2)) proper(splitAt(X1, X2)) -> splitAt(proper(X1), proper(X2)) proper(pair(X1, X2)) -> pair(proper(X1), proper(X2)) proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)) proper(afterNth(X1, X2)) -> afterNth(proper(X1), proper(X2)) proper(snd(X)) -> snd(proper(X)) proper(and(X1, X2)) -> and(proper(X1), proper(X2)) proper(fst(X)) -> fst(proper(X)) proper(head(X)) -> head(proper(X)) proper(natsFrom(X)) -> natsFrom(proper(X)) proper(s(X)) -> s(proper(X)) proper(sel(X1, X2)) -> sel(proper(X1), proper(X2)) proper(0) -> ok(0) proper(nil) -> ok(nil) proper(tail(X)) -> tail(proper(X)) proper(take(X1, X2)) -> take(proper(X1), proper(X2)) U11(ok(X1), ok(X2), ok(X3), ok(X4)) -> ok(U11(X1, X2, X3, X4)) U12(ok(X1), ok(X2)) -> ok(U12(X1, X2)) splitAt(ok(X1), ok(X2)) -> ok(splitAt(X1, X2)) pair(ok(X1), ok(X2)) -> ok(pair(X1, X2)) cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)) afterNth(ok(X1), ok(X2)) -> ok(afterNth(X1, X2)) snd(ok(X)) -> ok(snd(X)) and(ok(X1), ok(X2)) -> ok(and(X1, X2)) fst(ok(X)) -> ok(fst(X)) head(ok(X)) -> ok(head(X)) natsFrom(ok(X)) -> ok(natsFrom(X)) s(ok(X)) -> ok(s(X)) sel(ok(X1), ok(X2)) -> ok(sel(X1, X2)) tail(ok(X)) -> ok(tail(X)) take(ok(X1), ok(X2)) -> ok(take(X1, X2)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) Q is empty. Special symbols used for the transformation (see [GM04]): top: top_1, active: active_1, mark: mark_1, ok: ok_1, proper: proper_1 The replacement map contains the following entries: U11: {1} tt: empty set U12: {1} splitAt: {1, 2} pair: {1, 2} cons: {1} afterNth: {1, 2} snd: {1} and: {1} fst: {1} head: {1} natsFrom: {1} s: {1} sel: {1, 2} 0: empty set nil: empty set tail: {1} take: {1, 2} The QTRS contained all rules created by the complete Giesl-Middeldorp transformation. Therefore, the inverse transformation is complete (and sound). ---------------------------------------- (2) Obligation: Context-sensitive rewrite system: The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The replacement map contains the following entries: U11: {1} tt: empty set U12: {1} splitAt: {1, 2} pair: {1, 2} cons: {1} afterNth: {1, 2} snd: {1} and: {1} fst: {1} head: {1} natsFrom: {1} s: {1} sel: {1, 2} 0: empty set nil: empty set tail: {1} take: {1, 2} ---------------------------------------- (3) CSRInnermostProof (EQUIVALENT) The CSR is orthogonal. By [CS_Inn] we can switch to innermost. ---------------------------------------- (4) Obligation: Context-sensitive rewrite system: The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The replacement map contains the following entries: U11: {1} tt: empty set U12: {1} splitAt: {1, 2} pair: {1, 2} cons: {1} afterNth: {1, 2} snd: {1} and: {1} fst: {1} head: {1} natsFrom: {1} s: {1} sel: {1, 2} 0: empty set nil: empty set tail: {1} take: {1, 2} Innermost Strategy. ---------------------------------------- (5) CSDependencyPairsProof (EQUIVALENT) Using Improved CS-DPs [LPAR08] we result in the following initial Q-CSDP problem. ---------------------------------------- (6) Obligation: Q-restricted context-sensitive dependency pair problem: The symbols in {splitAt_2, pair_2, afterNth_2, snd_1, fst_1, head_1, natsFrom_1, s_1, sel_2, tail_1, take_2, SPLITAT_2, SND_1, AFTERNTH_2, HEAD_1, SEL_2, FST_1, TAKE_2, TAIL_1, NATSFROM_1} are replacing on all positions. For all symbols f in {U11_4, U12_2, cons_2, and_2, U12'_2, U11'_4, AND_2} we have mu(f) = {1}. The symbols in {U_1} are not replacing on any position. The ordinary context-sensitive dependency pairs DP_o are: U11'(tt, N, X, XS) -> U12'(splitAt(N, XS), X) U11'(tt, N, X, XS) -> SPLITAT(N, XS) AFTERNTH(N, XS) -> SND(splitAt(N, XS)) AFTERNTH(N, XS) -> SPLITAT(N, XS) SEL(N, XS) -> HEAD(afterNth(N, XS)) SEL(N, XS) -> AFTERNTH(N, XS) SPLITAT(s(N), cons(X, XS)) -> U11'(tt, N, X, XS) TAKE(N, XS) -> FST(splitAt(N, XS)) TAKE(N, XS) -> SPLITAT(N, XS) The collapsing dependency pairs are DP_c: U11'(tt, N, X, XS) -> N U11'(tt, N, X, XS) -> XS U12'(pair(YS, ZS), X) -> X AND(tt, X) -> X TAIL(cons(N, XS)) -> XS The hidden terms of R are: natsFrom(s(x0)) Every hiding context is built from: aprove.DPFramework.CSDPProblem.QCSDPProblem$1@57626ba3 aprove.DPFramework.CSDPProblem.QCSDPProblem$1@11987d48 Hence, the new unhiding pairs DP_u are : U11'(tt, N, X, XS) -> U(N) U11'(tt, N, X, XS) -> U(XS) U12'(pair(YS, ZS), X) -> U(X) AND(tt, X) -> U(X) TAIL(cons(N, XS)) -> U(XS) U(s(x_0)) -> U(x_0) U(natsFrom(x_0)) -> U(x_0) U(natsFrom(s(x0))) -> NATSFROM(s(x0)) The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The set Q consists of the following terms: U11(tt, x0, x1, x2) U12(pair(x0, x1), x2) afterNth(x0, x1) and(tt, x0) fst(pair(x0, x1)) head(cons(x0, x1)) natsFrom(x0) sel(x0, x1) snd(pair(x0, x1)) splitAt(0, x0) splitAt(s(x0), cons(x1, x2)) tail(cons(x0, x1)) take(x0, x1) ---------------------------------------- (7) QCSDependencyGraphProof (EQUIVALENT) The approximation of the Context-Sensitive Dependency Graph [LPAR08] contains 2 SCCs with 11 less nodes. ---------------------------------------- (8) Complex Obligation (AND) ---------------------------------------- (9) Obligation: Q-restricted context-sensitive dependency pair problem: The symbols in {splitAt_2, pair_2, afterNth_2, snd_1, fst_1, head_1, natsFrom_1, s_1, sel_2, tail_1, take_2} are replacing on all positions. For all symbols f in {U11_4, U12_2, cons_2, and_2} we have mu(f) = {1}. The symbols in {U_1} are not replacing on any position. The TRS P consists of the following rules: U(s(x_0)) -> U(x_0) U(natsFrom(x_0)) -> U(x_0) The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The set Q consists of the following terms: U11(tt, x0, x1, x2) U12(pair(x0, x1), x2) afterNth(x0, x1) and(tt, x0) fst(pair(x0, x1)) head(cons(x0, x1)) natsFrom(x0) sel(x0, x1) snd(pair(x0, x1)) splitAt(0, x0) splitAt(s(x0), cons(x1, x2)) tail(cons(x0, x1)) take(x0, x1) ---------------------------------------- (10) QCSDPSubtermProof (EQUIVALENT) We use the subterm processor [DA_EMMES]. The following pairs can be oriented strictly and are deleted. U(s(x_0)) -> U(x_0) U(natsFrom(x_0)) -> U(x_0) The remaining pairs can at least be oriented weakly. none Used ordering: Combined order from the following AFS and order. U(x1) = x1 Subterm Order ---------------------------------------- (11) Obligation: Q-restricted context-sensitive dependency pair problem: The symbols in {splitAt_2, pair_2, afterNth_2, snd_1, fst_1, head_1, natsFrom_1, s_1, sel_2, tail_1, take_2} are replacing on all positions. For all symbols f in {U11_4, U12_2, cons_2, and_2} we have mu(f) = {1}. The TRS P consists of the following rules: none The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The set Q consists of the following terms: U11(tt, x0, x1, x2) U12(pair(x0, x1), x2) afterNth(x0, x1) and(tt, x0) fst(pair(x0, x1)) head(cons(x0, x1)) natsFrom(x0) sel(x0, x1) snd(pair(x0, x1)) splitAt(0, x0) splitAt(s(x0), cons(x1, x2)) tail(cons(x0, x1)) take(x0, x1) ---------------------------------------- (12) PIsEmptyProof (EQUIVALENT) The TRS P is empty. Hence, there is no (P,Q,R,mu)-chain. ---------------------------------------- (13) YES ---------------------------------------- (14) Obligation: Q-restricted context-sensitive dependency pair problem: The symbols in {splitAt_2, pair_2, afterNth_2, snd_1, fst_1, head_1, natsFrom_1, s_1, sel_2, tail_1, take_2, SPLITAT_2} are replacing on all positions. For all symbols f in {U11_4, U12_2, cons_2, and_2, U11'_4} we have mu(f) = {1}. The TRS P consists of the following rules: U11'(tt, N, X, XS) -> SPLITAT(N, XS) SPLITAT(s(N), cons(X, XS)) -> U11'(tt, N, X, XS) The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The set Q consists of the following terms: U11(tt, x0, x1, x2) U12(pair(x0, x1), x2) afterNth(x0, x1) and(tt, x0) fst(pair(x0, x1)) head(cons(x0, x1)) natsFrom(x0) sel(x0, x1) snd(pair(x0, x1)) splitAt(0, x0) splitAt(s(x0), cons(x1, x2)) tail(cons(x0, x1)) take(x0, x1) ---------------------------------------- (15) QCSDPSubtermProof (EQUIVALENT) We use the subterm processor [DA_EMMES]. The following pairs can be oriented strictly and are deleted. SPLITAT(s(N), cons(X, XS)) -> U11'(tt, N, X, XS) The remaining pairs can at least be oriented weakly. U11'(tt, N, X, XS) -> SPLITAT(N, XS) Used ordering: Combined order from the following AFS and order. SPLITAT(x1, x2) = x1 U11'(x1, x2, x3, x4) = x2 Subterm Order ---------------------------------------- (16) Obligation: Q-restricted context-sensitive dependency pair problem: The symbols in {splitAt_2, pair_2, afterNth_2, snd_1, fst_1, head_1, natsFrom_1, s_1, sel_2, tail_1, take_2, SPLITAT_2} are replacing on all positions. For all symbols f in {U11_4, U12_2, cons_2, and_2, U11'_4} we have mu(f) = {1}. The TRS P consists of the following rules: U11'(tt, N, X, XS) -> SPLITAT(N, XS) The TRS R consists of the following rules: U11(tt, N, X, XS) -> U12(splitAt(N, XS), X) U12(pair(YS, ZS), X) -> pair(cons(X, YS), ZS) afterNth(N, XS) -> snd(splitAt(N, XS)) and(tt, X) -> X fst(pair(X, Y)) -> X head(cons(N, XS)) -> N natsFrom(N) -> cons(N, natsFrom(s(N))) sel(N, XS) -> head(afterNth(N, XS)) snd(pair(X, Y)) -> Y splitAt(0, XS) -> pair(nil, XS) splitAt(s(N), cons(X, XS)) -> U11(tt, N, X, XS) tail(cons(N, XS)) -> XS take(N, XS) -> fst(splitAt(N, XS)) The set Q consists of the following terms: U11(tt, x0, x1, x2) U12(pair(x0, x1), x2) afterNth(x0, x1) and(tt, x0) fst(pair(x0, x1)) head(cons(x0, x1)) natsFrom(x0) sel(x0, x1) snd(pair(x0, x1)) splitAt(0, x0) splitAt(s(x0), cons(x1, x2)) tail(cons(x0, x1)) take(x0, x1) ---------------------------------------- (17) QCSDependencyGraphProof (EQUIVALENT) The approximation of the Context-Sensitive Dependency Graph [LPAR08] contains 0 SCCs with 1 less node. ---------------------------------------- (18) TRUE