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: mem#(x, cons(y, l)) -> ifmem#(eq(x, y), x, l) ifmem#(false, x, l) -> mem#(x, l) rules: app(nil, l) -> l app(cons(x, l1), l2) -> cons(x, app(l1, l2)) app(app(l1, l2), l3) -> app(l1, app(l2, l3)) eq(0, 0) -> true eq(0, s(x)) -> false eq(s(x), 0) -> false eq(s(x), s(y)) -> eq(x, y) if(true, x, y) -> x if(false, x, y) -> y ifinter(true, x, l1, l2) -> cons(x, inter(l1, l2)) ifinter(false, x, l1, l2) -> inter(l1, l2) ifmem(true, x, l) -> true ifmem(false, x, l) -> mem(x, l) inter(x, nil) -> nil inter(nil, x) -> nil inter(app(l1, l2), l3) -> app(inter(l1, l3), inter(l2, l3)) inter(l1, app(l2, l3)) -> app(inter(l1, l2), inter(l1, l3)) inter(cons(x, l1), l2) -> ifinter(mem(x, l2), x, l1, l2) inter(l1, cons(x, l2)) -> ifinter(mem(x, l1), x, l2, l1) mem(x, nil) -> false mem(x, cons(y, l)) -> ifmem(eq(x, y), x, l) the pairs mem#(x, cons(y, l)) -> ifmem#(eq(x, y), x, l) ifmem#(false, x, l) -> mem#(x, l) could not apply the generic root reduction pair processor with the following SCNP-version with mu = MS and the level mapping defined by pi(mem#) = [(epsilon,0),(1,0)] pi(ifmem#) = [(epsilon,0),(2,0),(3,1)] Argument Filter: pi(mem#/2) = [2] pi(cons/2) = [2] pi(ifmem#/3) = [3] pi(eq/2) = [1,2] pi(false/0) = [] pi(0/0) = [] pi(true/0) = [] pi(s/1) = [] RPO with the following precedence precedence(mem#[2]) = 1 precedence(cons[2]) = 0 precedence(ifmem#[3]) = 1 precedence(eq[2]) = 0 precedence(false[0]) = 1 precedence(0[0]) = 1 precedence(true[0]) = 2 precedence(s[1]) = 1 precedence(_) = 0 and the following status status(mem#[2]) = lex status(cons[2]) = lex status(ifmem#[3]) = lex status(eq[2]) = lex status(false[0]) = lex status(0[0]) = lex status(true[0]) = lex status(s[1]) = lex status(_) = lex problem when orienting DPs cannot orient pair ifmem#(false, x, l) -> mem#(x, l) strictly: [(ifmem#(false, x, l),0),(x,0),(l,1)] >mu [(mem#(x, l),0),(x,0)] could not be ensured