0.02/0.09 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.02/0.09 % Command : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof 0.08/0.29 % Computer : n014.cluster.edu 0.08/0.29 % Model : x86_64 x86_64 0.08/0.29 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.08/0.29 % Memory : 8042.1875MB 0.08/0.29 % OS : Linux 3.10.0-693.el7.x86_64 0.08/0.29 % CPULimit : 1200 0.08/0.29 % WCLimit : 120 0.08/0.29 % DateTime : Tue Jul 13 13:20:04 EDT 2021 0.08/0.29 % CPUTime : 0.14/0.35 % SZS status Unsatisfiable 0.14/0.35 0.14/0.35 % SZS output start Proof 0.14/0.35 Axiom 1 (b_definition): apply(apply(apply(b, X), Y), Z) = apply(X, apply(Y, Z)). 0.14/0.35 Axiom 2 (n_definition): apply(apply(apply(n, X), Y), Z) = apply(apply(apply(X, Z), Y), Z). 0.14/0.35 0.14/0.35 Goal 1 (prove_fixed_point): apply(X, f(X)) = apply(f(X), apply(X, f(X))). 0.14/0.35 The goal is true when: 0.14/0.35 X = apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))) 0.14/0.35 0.14/0.35 Proof: 0.14/0.35 apply(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))) 0.14/0.35 = { by axiom 2 (n_definition) } 0.14/0.35 apply(apply(apply(apply(apply(b, apply(b, apply(n, b))), apply(n, apply(b, apply(b, apply(n, b))))), X), apply(n, apply(b, apply(b, apply(n, b))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))) 0.14/0.35 = { by axiom 1 (b_definition) } 0.14/0.35 apply(apply(apply(apply(b, apply(n, b)), apply(apply(n, apply(b, apply(b, apply(n, b)))), X)), apply(n, apply(b, apply(b, apply(n, b))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))) 0.14/0.35 = { by axiom 1 (b_definition) } 0.14/0.35 apply(apply(apply(n, b), apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b)))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))) 0.14/0.35 = { by axiom 2 (n_definition) } 0.14/0.35 apply(apply(apply(b, f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))), apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b)))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))))) 0.14/0.35 = { by axiom 1 (b_definition) } 0.14/0.35 apply(f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b)))))), apply(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b))))), f(apply(apply(apply(n, apply(b, apply(b, apply(n, b)))), X), apply(n, apply(b, apply(b, apply(n, b)))))))) 0.14/0.35 % SZS output end Proof 0.14/0.35 0.14/0.35 RESULT: Unsatisfiable (the axioms are contradictory). 0.14/0.36 EOF