YES TRS: del(.(x,.(y,z))) -> f(=(x,y),x,y,z) f(true(),x,y,z) -> del(.(y,z)) f(false(),x,y,z) -> .(x,del(.(y,z))) =(nil(),nil()) -> true() =(.(x,y),nil()) -> false() =(nil(),.(y,z)) -> false() =(.(x,y),.(u(),v())) -> and(=(x,u()),=(y,v())) linear polynomial interpretations on N: del_A(x1) = x1 del#_A(x1) = x1 + 1 ._A(x1,x2) = x1 + x2 + 2 .#_A(x1,x2) = 3 f_A(x1,x2,x3,x4) = x2 + x3 + x4 + 4 f#_A(x1,x2,x3,x4) = x2 + x3 + x4 + 4 =_A(x1,x2) = x1 + x2 + 1 =#_A(x1,x2) = 3 true_A = 3 true#_A = 2 false_A = 1 false#_A = 0 nil_A = 1 nil#_A = 1 u_A = 1 u#_A = 1 v_A = 1 v#_A = 0 and_A(x1,x2) = x1 + x2 and#_A(x1,x2) = 0 precedence: del = . > f = and > = > true = u > nil = v > false