YES We show the termination of the TRS R: a(lambda(x),y) -> lambda(a(x,|1|())) a(lambda(x),y) -> lambda(a(x,a(y,t()))) a(a(x,y),z) -> a(x,a(y,z)) lambda(x) -> x a(x,y) -> x a(x,y) -> y -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> lambda#(a(x,|1|())) p2: a#(lambda(x),y) -> a#(x,|1|()) p3: a#(lambda(x),y) -> lambda#(a(x,a(y,t()))) p4: a#(lambda(x),y) -> a#(x,a(y,t())) p5: a#(lambda(x),y) -> a#(y,t()) p6: a#(a(x,y),z) -> a#(x,a(y,z)) p7: a#(a(x,y),z) -> a#(y,z) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The estimated dependency graph contains the following SCCs: {p2, p4, p5, p6, p7} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> a#(x,|1|()) p2: a#(a(x,y),z) -> a#(y,z) p3: a#(a(x,y),z) -> a#(x,a(y,z)) p4: a#(lambda(x),y) -> a#(y,t()) p5: a#(lambda(x),y) -> a#(x,a(y,t())) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The set of usable rules consists of r1, r2, r3, r4, r5, r6 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (2,3) lambda_A(x1) = ((1,0),(0,0)) x1 + (3,2) |1|_A() = (0,1) a_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (0,2) t_A() = (0,6) precedence: lambda = |1| = a > a# = t partial status: pi(a#) = [1] pi(lambda) = [] pi(|1|) = [] pi(a) = [] pi(t) = [] The next rules are strictly ordered: p5 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> a#(x,|1|()) p2: a#(a(x,y),z) -> a#(y,z) p3: a#(a(x,y),z) -> a#(x,a(y,z)) p4: a#(lambda(x),y) -> a#(y,t()) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> a#(x,|1|()) p2: a#(lambda(x),y) -> a#(y,t()) p3: a#(a(x,y),z) -> a#(x,a(y,z)) p4: a#(a(x,y),z) -> a#(y,z) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The set of usable rules consists of r1, r2, r3, r4, r5, r6 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = ((0,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (1,2) lambda_A(x1) = ((1,0),(0,0)) x1 + (2,1) |1|_A() = (0,2) t_A() = (0,0) a_A(x1,x2) = ((1,0),(1,1)) x1 + x2 precedence: lambda = |1| = t = a > a# partial status: pi(a#) = [] pi(lambda) = [] pi(|1|) = [] pi(t) = [] pi(a) = [] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> a#(y,t()) p2: a#(a(x,y),z) -> a#(x,a(y,z)) p3: a#(a(x,y),z) -> a#(y,z) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(lambda(x),y) -> a#(y,t()) p2: a#(a(x,y),z) -> a#(y,z) p3: a#(a(x,y),z) -> a#(x,a(y,z)) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The set of usable rules consists of r1, r2, r3, r4, r5, r6 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = ((0,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (1,1) lambda_A(x1) = ((1,0),(0,0)) x1 + (2,7) t_A() = (0,4) a_A(x1,x2) = x1 + x2 + (0,2) |1|_A() = (0,6) precedence: a# = lambda = a > t = |1| partial status: pi(a#) = [] pi(lambda) = [] pi(t) = [] pi(a) = [] pi(|1|) = [] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(a(x,y),z) -> a#(y,z) p2: a#(a(x,y),z) -> a#(x,a(y,z)) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(a(x,y),z) -> a#(y,z) p2: a#(a(x,y),z) -> a#(x,a(y,z)) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The set of usable rules consists of r1, r2, r3, r4, r5, r6 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = x1 + (1,1) a_A(x1,x2) = x1 + x2 + (0,2) lambda_A(x1) = ((1,0),(0,0)) x1 + (1,3) |1|_A() = (0,6) t_A() = (0,0) precedence: a# = a = lambda = |1| > t partial status: pi(a#) = [] pi(a) = [] pi(lambda) = [] pi(|1|) = [] pi(t) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(a(x,y),z) -> a#(y,z) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(a(x,y),z) -> a#(y,z) and R consists of: r1: a(lambda(x),y) -> lambda(a(x,|1|())) r2: a(lambda(x),y) -> lambda(a(x,a(y,t()))) r3: a(a(x,y),z) -> a(x,a(y,z)) r4: lambda(x) -> x r5: a(x,y) -> x r6: a(x,y) -> y The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = ((1,0),(0,0)) x1 + (1,1) a_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(0,0)) x2 + (2,2) precedence: a# = a partial status: pi(a#) = [] pi(a) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.