YES We show the termination of the TRS R: app(app(apply(),f),x) -> app(f,x) Instead we prove termination of the uncurried system: app(apply_0(),y) -> apply_1(y) app(apply_1(x1),y) -> apply_2(x1,y) apply_2(f,x) -> app(f,x) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(apply_1(x1),y) -> apply_2#(x1,y) p2: apply_2#(f,x) -> app#(f,x) and R consists of: r1: app(apply_0(),y) -> apply_1(y) r2: app(apply_1(x1),y) -> apply_2(x1,y) r3: apply_2(f,x) -> app(f,x) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(apply_1(x1),y) -> apply_2#(x1,y) p2: apply_2#(f,x) -> app#(f,x) and R consists of: r1: app(apply_0(),y) -> apply_1(y) r2: app(apply_1(x1),y) -> apply_2(x1,y) r3: apply_2(f,x) -> app(f,x) The set of usable rules consists of r1, r2, r3 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: model-based reduction triple (=A, >=A!, >A!): finite algebra: carrier: {0,1} interpretations: app#_A(0,0) = 0 app#_A(0,1) = 0 app#_A(1,0) = 0 app#_A(1,1) = 0 apply_1_A(0) = 0 apply_1_A(1) = 0 apply_2#_A(0,0) = 0 apply_2#_A(0,1) = 0 apply_2#_A(1,0) = 0 apply_2#_A(1,1) = 0 app_A(0,0) = 0 app_A(0,1) = 0 app_A(1,0) = 0 app_A(1,1) = 0 apply_0_A = 0 apply_2_A(0,0) = 0 apply_2_A(0,1) = 0 apply_2_A(1,0) = 0 apply_2_A(1,1) = 0 app#!_A(0,0) = 1 app#!_A(0,1) = 1 app#!_A(1,0) = 0 app#!_A(1,1) = 0 apply_1!_A(0) = 1 apply_1!_A(1) = 0 apply_2#!_A(0,0) = 1 apply_2#!_A(0,1) = 1 apply_2#!_A(1,0) = 0 apply_2#!_A(1,1) = 0 app!_A(0,0) = 1 app!_A(0,1) = 0 app!_A(1,0) = 0 app!_A(1,1) = 0 apply_0!_A = 0 apply_2!_A(0,0) = 1 apply_2!_A(0,1) = 0 apply_2!_A(1,0) = 0 apply_2!_A(1,1) = 0 partial status: pi(app#) = [1] pi(apply_1) = [1] pi(apply_2#) = [1] pi(app) = [2] pi(apply_0) = [] pi(apply_2) = [2] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: apply_2#(f,x) -> app#(f,x) and R consists of: r1: app(apply_0(),y) -> apply_1(y) r2: app(apply_1(x1),y) -> apply_2(x1,y) r3: apply_2(f,x) -> app(f,x) The estimated dependency graph contains the following SCCs: (no SCCs)