0.10/0.11 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.10/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.33 % Computer : n003.cluster.edu 0.12/0.33 % Model : x86_64 x86_64 0.12/0.33 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.12/0.33 % Memory : 8042.1875MB 0.12/0.33 % OS : Linux 3.10.0-693.el7.x86_64 0.12/0.33 % CPULimit : 180 0.12/0.33 % DateTime : Thu Aug 29 11:56:02 EDT 2019 0.12/0.33 % CPUTime : 19.53/19.68 % SZS status Unsatisfiable 19.53/19.68 19.53/19.68 % SZS output start Proof 19.53/19.68 Take the following subset of the input axioms: 19.53/19.68 fof(ax2_4304, axiom, genls(c_tptpcol_16_130924, c_tptpcol_15_130923)=true). 19.53/19.68 fof(goal, negated_conjecture, b!=a). 19.53/19.68 fof(ifeq_axiom_001, axiom, ![A, B, C]: ifeq3(A, A, B, C)=B). 19.53/19.68 fof(query172_1, negated_conjecture, ifeq3(genls(c_tptpcol_16_130924, c_tptpcol_15_130923), true, a, b)=b). 19.53/19.68 19.53/19.68 Now clausify the problem and encode Horn clauses using encoding 3 of 19.53/19.68 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 19.53/19.68 We repeatedly replace C & s=t => u=v by the two clauses: 19.53/19.68 fresh(y, y, x1...xn) = u 19.53/19.68 C => fresh(s, t, x1...xn) = v 19.53/19.68 where fresh is a fresh function symbol and x1..xn are the free 19.53/19.68 variables of u and v. 19.53/19.68 A predicate p(X) is encoded as p(X)=true (this is sound, because the 19.53/19.68 input problem has no model of domain size 1). 19.53/19.68 19.53/19.68 The encoding turns the above axioms into the following unit equations and goals: 19.53/19.68 19.53/19.68 Axiom 1 (ifeq_axiom_001): ifeq3(X, X, Y, Z) = Y. 19.53/19.68 Axiom 2 (ax2_4304): genls(c_tptpcol_16_130924, c_tptpcol_15_130923) = true. 19.53/19.68 Axiom 3 (query172_1): ifeq3(genls(c_tptpcol_16_130924, c_tptpcol_15_130923), true, a, b) = b. 19.53/19.68 19.53/19.68 Goal 1 (goal): b = a. 19.53/19.68 Proof: 19.53/19.68 b 19.53/19.68 = { by axiom 3 (query172_1) } 19.53/19.68 ifeq3(genls(c_tptpcol_16_130924, c_tptpcol_15_130923), true, a, b) 19.53/19.68 = { by axiom 2 (ax2_4304) } 19.53/19.68 ifeq3(true, true, a, b) 19.53/19.68 = { by axiom 1 (ifeq_axiom_001) } 19.53/19.68 a 19.53/19.68 % SZS output end Proof 19.53/19.68 19.53/19.68 RESULT: Unsatisfiable (the axioms are contradictory). 19.53/19.75 EOF