YES TPA v.1.0 Result: TRS is terminating Default interpretations for symbols are not printed. For polynomial interpretations and semantic labelling over N\{0,1} defaults are 2 for constants, identity for unary symbols and x+y-2 for binary symbols. For semantic labelling over {0,1} (booleans) defaults are 0 for constants, identity for unary symbols and disjunction for binary symbols. [1] TRS loaded from input file: (1) b(x) ->= b(b(x)) (2) a(b(a(x))) -> a(b(b(a(x)))) [2] Label this TRS using following interpretation that is a model: [b(x)] = 0 [a(x)] = 1 rest default thus obtaining new TRS: (1a) b$1(x) ->= b$0(b$1(x)) (1b) b$0(x) ->= b$0(b$0(x)) (2a) a$0(b$1(a$1(x))) -> a$0(b$0(b$1(a$1(x)))) (2b) a$0(b$1(a$0(x))) -> a$0(b$0(b$1(a$0(x)))) [3] Reverse every lhs and rhs of the rule to obtain the following TRS: (1a) b$1(x) ->= b$1(b$0(x)) (1b) b$0(x) ->= b$0(b$0(x)) (2a) a$1(b$1(a$0(x))) -> a$1(b$1(b$0(a$0(x)))) (2b) a$0(b$1(a$0(x))) -> a$0(b$1(b$0(a$0(x)))) [4] Label this TRS using following interpretation over N\{0,1}: [b$0(x)] = 2 [b$1(x)] = 2 [a$0(x)] = x + 1 [a$1(x)] = 2 rest default This interpretation is a model and yields following TRS: (1a) b$1{j}(x) ->= b$1{2}(b$0{j}(x)) (1b) b$0{j}(x) ->= b$0{2}(b$0{j}(x)) (2a) a$1{2}(b$1{j + 1}(a$0{j}(x))) -> a$1{2}(b$1{2}(b$0{j + 1}(a$0{j}(x)))) (2b) a$0{2}(b$1{j + 1}(a$0{j}(x))) -> a$0{2}(b$1{2}(b$0{j + 1}(a$0{j}(x)))) [5] Use following polynomial interpretation: [b$0_{i}(x)] = x [b$1_{i}(x)] = x + i [a$0_{i}(x)] = x [a$1_{i}(x)] = x rest default Remove rules with left hand side strictly bigger than right hand side: (2a)-(2b) [6] Since there are no remaining rules, termination is proved! ../qualif/zr05.srs, 0.01, Y Couldn't open file <60>: 60: No such file or directory