ceta_eq: termination proof not accepted 1: error below switch to dependency pairs 1.1: error below the dependency graph processor 1.1.2: error when applying the reduction pair processor with usable rules to remove from the DP problem pairs: eq#(mark(X1), X2) -> eq#(X1, X2) eq#(X1, mark(X2)) -> eq#(X1, X2) eq#(active(X1), X2) -> eq#(X1, X2) eq#(X1, active(X2)) -> eq#(X1, X2) rules: active(eq(0, 0)) -> mark(true) active(eq(s(X), s(Y))) -> mark(eq(X, Y)) active(eq(X, Y)) -> mark(false) active(inf(X)) -> mark(cons(X, inf(s(X)))) active(take(0, X)) -> mark(nil) active(take(s(X), cons(Y, L))) -> mark(cons(Y, take(X, L))) active(length(nil)) -> mark(0) active(length(cons(X, L))) -> mark(s(length(L))) cons(mark(X1), X2) -> cons(X1, X2) cons(X1, mark(X2)) -> cons(X1, X2) cons(active(X1), X2) -> cons(X1, X2) cons(X1, active(X2)) -> cons(X1, X2) eq(mark(X1), X2) -> eq(X1, X2) eq(X1, mark(X2)) -> eq(X1, X2) eq(active(X1), X2) -> eq(X1, X2) eq(X1, active(X2)) -> eq(X1, X2) inf(mark(X)) -> inf(X) inf(active(X)) -> inf(X) length(mark(X)) -> length(X) length(active(X)) -> length(X) mark(eq(X1, X2)) -> active(eq(X1, X2)) mark(0) -> active(0) mark(true) -> active(true) mark(s(X)) -> active(s(X)) mark(false) -> active(false) mark(inf(X)) -> active(inf(mark(X))) mark(cons(X1, X2)) -> active(cons(X1, X2)) mark(take(X1, X2)) -> active(take(mark(X1), mark(X2))) mark(nil) -> active(nil) mark(length(X)) -> active(length(mark(X))) s(mark(X)) -> s(X) s(active(X)) -> s(X) take(mark(X1), X2) -> take(X1, X2) take(X1, mark(X2)) -> take(X1, X2) take(active(X1), X2) -> take(X1, X2) take(X1, active(X2)) -> take(X1, X2) the pairs eq#(active(X1), X2) -> eq#(X1, X2) could not apply the generic root reduction pair processor with the following SCNP-version with mu = MS and the level mapping defined by pi(eq#) = [(epsilon,0),(1,1)] Argument Filter: pi(eq#/2) = [] pi(mark/1) = 1 pi(active/1) = [1] RPO with the following precedence precedence(eq#[2]) = 0 precedence(active[1]) = 1 precedence(_) = 0 and the following status status(eq#[2]) = lex status(active[1]) = lex status(_) = lex problem when orienting DPs cannot orient pair eq#(mark(X1), X2) -> eq#(X1, X2) weakly: [(eq#(mark(X1), X2),0),(mark(X1),1)] >=mu [(eq#(X1, X2),0),(X1,1)] could not be ensured