0.07/0.11 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.07/0.12 % Command : parallel-twee %s --tstp --conditional-encoding if --smaller --drop-non-horn --give-up-on-saturation --explain-encoding --formal-proof 0.11/0.33 % Computer : n014.cluster.edu 0.11/0.33 % Model : x86_64 x86_64 0.11/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.11/0.33 % Memory : 8042.1875MB 0.11/0.33 % OS : Linux 3.10.0-693.el7.x86_64 0.11/0.33 % CPULimit : 1200 0.11/0.33 % WCLimit : 120 0.11/0.33 % DateTime : Tue Jul 13 15:21:49 EDT 2021 0.11/0.33 % CPUTime : 1.77/0.60 % SZS status Unsatisfiable 1.77/0.60 1.77/0.61 % SZS output start Proof 1.77/0.61 Axiom 1 (k_definition): apply(apply(k, X), Y) = X. 1.77/0.61 Axiom 2 (s_definition): apply(apply(apply(s, X), Y), Z) = apply(apply(X, Z), apply(Y, Z)). 1.77/0.61 1.77/0.61 Goal 1 (prove_fixed_point): X = apply(combinator, X). 1.77/0.61 The goal is true when: 1.77/0.61 X = apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)))) 1.77/0.61 1.77/0.61 Proof: 1.77/0.61 apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)))) 1.77/0.61 = { by axiom 2 (s_definition) } 1.77/0.61 apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(k, apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))), apply(X, apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))))) 1.77/0.61 = { by axiom 1 (k_definition) } 1.77/0.61 apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))) 1.77/0.61 = { by axiom 2 (s_definition) } 1.77/0.61 apply(apply(apply(s, apply(k, combinator)), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)))) 1.77/0.61 = { by axiom 2 (s_definition) } 1.77/0.61 apply(apply(apply(k, combinator), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)))), apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))))) 1.77/0.61 = { by axiom 1 (k_definition) } 1.77/0.61 apply(combinator, apply(apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X)), apply(apply(apply(s, k), X), apply(apply(s, apply(s, apply(k, combinator))), apply(apply(s, k), X))))) 1.77/0.61 % SZS output end Proof 1.77/0.61 1.77/0.61 RESULT: Unsatisfiable (the axioms are contradictory). 1.77/0.61 EOF