We consider the system Applicative_AG01_innermost__#4.36. Alphabet: 0 : [] --> b cons : [b * c] --> c eq : [b * b] --> a false : [] --> a filter : [b -> a * c] --> c filter2 : [a * b -> a * b * c] --> c if!fac6220min : [a * c] --> b if!fac6220replace : [a * b * b * c] --> c le : [b * b] --> a map : [b -> b * c] --> c min : [c] --> b nil : [] --> c replace : [b * b * c] --> c s : [b] --> b sort : [c] --> c true : [] --> a Rules: eq(0, 0) => true eq(0, s(x)) => false eq(s(x), 0) => false eq(s(x), s(y)) => eq(x, y) le(0, x) => true le(s(x), 0) => false le(s(x), s(y)) => le(x, y) min(cons(0, nil)) => 0 min(cons(s(x), nil)) => s(x) min(cons(x, cons(y, z))) => if!fac6220min(le(x, y), cons(x, cons(y, z))) if!fac6220min(true, cons(x, cons(y, z))) => min(cons(x, z)) if!fac6220min(false, cons(x, cons(y, z))) => min(cons(y, z)) replace(x, y, nil) => nil replace(x, y, cons(z, u)) => if!fac6220replace(eq(x, z), x, y, cons(z, u)) if!fac6220replace(true, x, y, cons(z, u)) => cons(y, u) if!fac6220replace(false, x, y, cons(z, u)) => cons(z, replace(x, y, u)) sort(nil) => nil sort(cons(x, y)) => cons(min(cons(x, y)), sort(replace(min(cons(x, y)), x, y))) map(f, nil) => nil map(f, cons(x, y)) => cons(f x, map(f, y)) filter(f, nil) => nil filter(f, cons(x, y)) => filter2(f x, f, x, y) filter2(true, f, x, y) => cons(x, filter(f, y)) filter2(false, f, x, y) => filter(f, y) This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). We observe that the rules contain a first-order subset: eq(0, 0) => true eq(0, s(X)) => false eq(s(X), 0) => false eq(s(X), s(Y)) => eq(X, Y) le(0, X) => true le(s(X), 0) => false le(s(X), s(Y)) => le(X, Y) min(cons(0, nil)) => 0 min(cons(s(X), nil)) => s(X) min(cons(X, cons(Y, Z))) => if!fac6220min(le(X, Y), cons(X, cons(Y, Z))) if!fac6220min(true, cons(X, cons(Y, Z))) => min(cons(X, Z)) if!fac6220min(false, cons(X, cons(Y, Z))) => min(cons(Y, Z)) replace(X, Y, nil) => nil replace(X, Y, cons(Z, U)) => if!fac6220replace(eq(X, Z), X, Y, cons(Z, U)) if!fac6220replace(true, X, Y, cons(Z, U)) => cons(Y, U) if!fac6220replace(false, X, Y, cons(Z, U)) => cons(Z, replace(X, Y, U)) sort(nil) => nil sort(cons(X, Y)) => cons(min(cons(X, Y)), sort(replace(min(cons(X, Y)), X, Y))) Moreover, the system is orthogonal. Thus, by [Kop12, Thm. 7.55], we may omit all first-order dependency pairs from the dependency pair problem (DP(R), R) if this first-order part is terminating when seen as a many-sorted first-order TRS. According to mutermprover, this system is indeed terminating: || || Problem 1: || || (VAR %U %X %Y %Z) || (RULES || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ) || || Problem 1: || || Innermost Equivalent Processor: || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || -> The term rewriting system is non-overlaping or locally confluent overlay system. Therefore, innermost termination implies termination. || || || Problem 1: || || Dependency Pairs Processor: || -> Pairs: || EQ(s(%X),s(%Y)) -> EQ(%X,%Y) || IF!FAC6220MIN(false,cons(%X,cons(%Y,%Z))) -> MIN(cons(%Y,%Z)) || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || IF!FAC6220REPLACE(false,%X,%Y,cons(%Z,%U)) -> REPLACE(%X,%Y,%U) || LE(s(%X),s(%Y)) -> LE(%X,%Y) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || MIN(cons(%X,cons(%Y,%Z))) -> LE(%X,%Y) || REPLACE(%X,%Y,cons(%Z,%U)) -> EQ(%X,%Z) || REPLACE(%X,%Y,cons(%Z,%U)) -> IF!FAC6220REPLACE(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || SORT(cons(%X,%Y)) -> MIN(cons(%X,%Y)) || SORT(cons(%X,%Y)) -> REPLACE(min(cons(%X,%Y)),%X,%Y) || SORT(cons(%X,%Y)) -> SORT(replace(min(cons(%X,%Y)),%X,%Y)) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || || Problem 1: || || SCC Processor: || -> Pairs: || EQ(s(%X),s(%Y)) -> EQ(%X,%Y) || IF!FAC6220MIN(false,cons(%X,cons(%Y,%Z))) -> MIN(cons(%Y,%Z)) || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || IF!FAC6220REPLACE(false,%X,%Y,cons(%Z,%U)) -> REPLACE(%X,%Y,%U) || LE(s(%X),s(%Y)) -> LE(%X,%Y) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || MIN(cons(%X,cons(%Y,%Z))) -> LE(%X,%Y) || REPLACE(%X,%Y,cons(%Z,%U)) -> EQ(%X,%Z) || REPLACE(%X,%Y,cons(%Z,%U)) -> IF!FAC6220REPLACE(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || SORT(cons(%X,%Y)) -> MIN(cons(%X,%Y)) || SORT(cons(%X,%Y)) -> REPLACE(min(cons(%X,%Y)),%X,%Y) || SORT(cons(%X,%Y)) -> SORT(replace(min(cons(%X,%Y)),%X,%Y)) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || ->->Cycle: || ->->-> Pairs: || LE(s(%X),s(%Y)) -> LE(%X,%Y) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->->Cycle: || ->->-> Pairs: || IF!FAC6220MIN(false,cons(%X,cons(%Y,%Z))) -> MIN(cons(%Y,%Z)) || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->->Cycle: || ->->-> Pairs: || EQ(s(%X),s(%Y)) -> EQ(%X,%Y) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->->Cycle: || ->->-> Pairs: || IF!FAC6220REPLACE(false,%X,%Y,cons(%Z,%U)) -> REPLACE(%X,%Y,%U) || REPLACE(%X,%Y,cons(%Z,%U)) -> IF!FAC6220REPLACE(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->->Cycle: || ->->-> Pairs: || SORT(cons(%X,%Y)) -> SORT(replace(min(cons(%X,%Y)),%X,%Y)) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || || || The problem is decomposed in 5 subproblems. || || Problem 1.1: || || Subterm Processor: || -> Pairs: || LE(s(%X),s(%Y)) -> LE(%X,%Y) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Projection: || pi(LE) = 1 || || Problem 1.1: || || SCC Processor: || -> Pairs: || Empty || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || There is no strongly connected component || || The problem is finite. || || Problem 1.2: || || Reduction Pairs Processor: || -> Pairs: || IF!FAC6220MIN(false,cons(%X,cons(%Y,%Z))) -> MIN(cons(%Y,%Z)) || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || -> Usable rules: || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || ->Interpretation type: || Linear || ->Coefficients: || Natural Numbers || ->Dimension: || 1 || ->Bound: || 2 || ->Interpretation: || || [le](X1,X2) = 2.X1 + 2.X2 + 2 || [0] = 2 || [cons](X1,X2) = 2.X1 + 2.X2 + 2 || [false] = 0 || [s](X) = 2.X || [true] = 2 || [IF!FAC6220MIN](X1,X2) = 2.X2 + 1 || [MIN](X) = 2.X + 1 || || Problem 1.2: || || SCC Processor: || -> Pairs: || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || ->->Cycle: || ->->-> Pairs: || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || ->->-> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || || Problem 1.2: || || Reduction Pairs Processor: || -> Pairs: || IF!FAC6220MIN(true,cons(%X,cons(%Y,%Z))) -> MIN(cons(%X,%Z)) || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || -> Usable rules: || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || ->Interpretation type: || Linear || ->Coefficients: || Natural Numbers || ->Dimension: || 1 || ->Bound: || 2 || ->Interpretation: || || [le](X1,X2) = 1 || [0] = 1 || [cons](X1,X2) = 2.X1 + 2.X2 + 2 || [false] = 1 || [s](X) = 0 || [true] = 1 || [IF!FAC6220MIN](X1,X2) = 2.X1 + 2.X2 || [MIN](X) = 2.X + 2 || || Problem 1.2: || || SCC Processor: || -> Pairs: || MIN(cons(%X,cons(%Y,%Z))) -> IF!FAC6220MIN(le(%X,%Y),cons(%X,cons(%Y,%Z))) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || There is no strongly connected component || || The problem is finite. || || Problem 1.3: || || Subterm Processor: || -> Pairs: || EQ(s(%X),s(%Y)) -> EQ(%X,%Y) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Projection: || pi(EQ) = 1 || || Problem 1.3: || || SCC Processor: || -> Pairs: || Empty || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || There is no strongly connected component || || The problem is finite. || || Problem 1.4: || || Subterm Processor: || -> Pairs: || IF!FAC6220REPLACE(false,%X,%Y,cons(%Z,%U)) -> REPLACE(%X,%Y,%U) || REPLACE(%X,%Y,cons(%Z,%U)) -> IF!FAC6220REPLACE(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Projection: || pi(IF!FAC6220REPLACE) = 4 || pi(REPLACE) = 3 || || Problem 1.4: || || SCC Processor: || -> Pairs: || REPLACE(%X,%Y,cons(%Z,%U)) -> IF!FAC6220REPLACE(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || There is no strongly connected component || || The problem is finite. || || Problem 1.5: || || Reduction Pairs Processor: || -> Pairs: || SORT(cons(%X,%Y)) -> SORT(replace(min(cons(%X,%Y)),%X,%Y)) || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || -> Usable rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || ->Interpretation type: || Linear || ->Coefficients: || Natural Numbers || ->Dimension: || 1 || ->Bound: || 2 || ->Interpretation: || || [eq](X1,X2) = 1 || [if!fac6220min](X1,X2) = 2.X2 || [if!fac6220replace](X1,X2,X3,X4) = X1 + 2.X4 || [le](X1,X2) = 1 || [min](X) = 2.X || [replace](X1,X2,X3) = 2.X3 + 1 || [0] = 0 || [cons](X1,X2) = 2.X2 + 2 || [false] = 1 || [nil] = 2 || [s](X) = 0 || [true] = 1 || [SORT](X) = 2.X || || Problem 1.5: || || SCC Processor: || -> Pairs: || Empty || -> Rules: || eq(0,0) -> true || eq(0,s(%X)) -> false || eq(s(%X),0) -> false || eq(s(%X),s(%Y)) -> eq(%X,%Y) || if!fac6220min(false,cons(%X,cons(%Y,%Z))) -> min(cons(%Y,%Z)) || if!fac6220min(true,cons(%X,cons(%Y,%Z))) -> min(cons(%X,%Z)) || if!fac6220replace(false,%X,%Y,cons(%Z,%U)) -> cons(%Z,replace(%X,%Y,%U)) || if!fac6220replace(true,%X,%Y,cons(%Z,%U)) -> cons(%Y,%U) || le(0,%X) -> true || le(s(%X),0) -> false || le(s(%X),s(%Y)) -> le(%X,%Y) || min(cons(0,nil)) -> 0 || min(cons(s(%X),nil)) -> s(%X) || min(cons(%X,cons(%Y,%Z))) -> if!fac6220min(le(%X,%Y),cons(%X,cons(%Y,%Z))) || replace(%X,%Y,cons(%Z,%U)) -> if!fac6220replace(eq(%X,%Z),%X,%Y,cons(%Z,%U)) || replace(%X,%Y,nil) -> nil || sort(cons(%X,%Y)) -> cons(min(cons(%X,%Y)),sort(replace(min(cons(%X,%Y)),%X,%Y))) || sort(nil) -> nil || ->Strongly Connected Components: || There is no strongly connected component || || The problem is finite. || We use the dependency pair framework as described in [Kop12, Ch. 6/7], with static dependency pairs (see [KusIsoSakBla09] and the adaptation for AFSMs and accessible arguments in [FuhKop19]). We thus obtain the following dependency pair problem (P_0, R_0, computable, formative): Dependency Pairs P_0: 0] map#(F, cons(X, Y)) =#> map#(F, Y) 1] filter#(F, cons(X, Y)) =#> filter2#(F X, F, X, Y) 2] filter2#(true, F, X, Y) =#> filter#(F, Y) 3] filter2#(false, F, X, Y) =#> filter#(F, Y) Rules R_0: eq(0, 0) => true eq(0, s(X)) => false eq(s(X), 0) => false eq(s(X), s(Y)) => eq(X, Y) le(0, X) => true le(s(X), 0) => false le(s(X), s(Y)) => le(X, Y) min(cons(0, nil)) => 0 min(cons(s(X), nil)) => s(X) min(cons(X, cons(Y, Z))) => if!fac6220min(le(X, Y), cons(X, cons(Y, Z))) if!fac6220min(true, cons(X, cons(Y, Z))) => min(cons(X, Z)) if!fac6220min(false, cons(X, cons(Y, Z))) => min(cons(Y, Z)) replace(X, Y, nil) => nil replace(X, Y, cons(Z, U)) => if!fac6220replace(eq(X, Z), X, Y, cons(Z, U)) if!fac6220replace(true, X, Y, cons(Z, U)) => cons(Y, U) if!fac6220replace(false, X, Y, cons(Z, U)) => cons(Z, replace(X, Y, U)) sort(nil) => nil sort(cons(X, Y)) => cons(min(cons(X, Y)), sort(replace(min(cons(X, Y)), X, Y))) map(F, nil) => nil map(F, cons(X, Y)) => cons(F X, map(F, Y)) filter(F, nil) => nil filter(F, cons(X, Y)) => filter2(F X, F, X, Y) filter2(true, F, X, Y) => cons(X, filter(F, Y)) filter2(false, F, X, Y) => filter(F, Y) Thus, the original system is terminating if (P_0, R_0, computable, formative) is finite. We consider the dependency pair problem (P_0, R_0, computable, formative). We place the elements of P in a dependency graph approximation G (see e.g. [Kop12, Thm. 7.27, 7.29], as follows: * 0 : 0 * 1 : 2, 3 * 2 : 1 * 3 : 1 This graph has the following strongly connected components: P_1: map#(F, cons(X, Y)) =#> map#(F, Y) P_2: filter#(F, cons(X, Y)) =#> filter2#(F X, F, X, Y) filter2#(true, F, X, Y) =#> filter#(F, Y) filter2#(false, F, X, Y) =#> filter#(F, Y) By [Kop12, Thm. 7.31], we may replace any dependency pair problem (P_0, R_0, m, f) by (P_1, R_0, m, f) and (P_2, R_0, m, f). Thus, the original system is terminating if each of (P_1, R_0, computable, formative) and (P_2, R_0, computable, formative) is finite. We consider the dependency pair problem (P_2, R_0, computable, formative). We apply the subterm criterion with the following projection function: nu(filter2#) = 4 nu(filter#) = 2 Thus, we can orient the dependency pairs as follows: nu(filter#(F, cons(X, Y))) = cons(X, Y) |> Y = nu(filter2#(F X, F, X, Y)) nu(filter2#(true, F, X, Y)) = Y = Y = nu(filter#(F, Y)) nu(filter2#(false, F, X, Y)) = Y = Y = nu(filter#(F, Y)) By [FuhKop19, Thm. 61], we may replace a dependency pair problem (P_2, R_0, computable, f) by (P_3, R_0, computable, f), where P_3 contains: filter2#(true, F, X, Y) =#> filter#(F, Y) filter2#(false, F, X, Y) =#> filter#(F, Y) Thus, the original system is terminating if each of (P_1, R_0, computable, formative) and (P_3, R_0, computable, formative) is finite. We consider the dependency pair problem (P_3, R_0, computable, formative). We place the elements of P in a dependency graph approximation G (see e.g. [Kop12, Thm. 7.27, 7.29], as follows: * 0 : * 1 : This graph has no strongly connected components. By [Kop12, Thm. 7.31], this implies finiteness of the dependency pair problem. Thus, the original system is terminating if (P_1, R_0, computable, formative) is finite. We consider the dependency pair problem (P_1, R_0, computable, formative). We apply the subterm criterion with the following projection function: nu(map#) = 2 Thus, we can orient the dependency pairs as follows: nu(map#(F, cons(X, Y))) = cons(X, Y) |> Y = nu(map#(F, Y)) By [FuhKop19, Thm. 61], we may replace a dependency pair problem (P_1, R_0, computable, f) by ({}, R_0, computable, f). By the empty set processor [Kop12, Thm. 7.15] this problem may be immediately removed. As all dependency pair problems were succesfully simplified with sound (and complete) processors until nothing remained, we conclude termination. +++ Citations +++ [FuhKop19] C. Fuhs, and C. Kop. A static higher-order dependency pair framework. In Proceedings of ESOP 2019, 2019. [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. [KusIsoSakBla09] K. Kusakari, Y. Isogai, M. Sakai, and F. Blanqui. Static Dependency Pair Method Based On Strong Computability for Higher-Order Rewrite Systems. In volume 92(10) of IEICE Transactions on Information and Systems. 2007--2015, 2009.