0.00/0.04 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.00/0.05 % Command : twee %s --tstp --casc --quiet --conditional-encoding if --smaller --drop-non-horn 0.03/0.29 % Computer : n133.star.cs.uiowa.edu 0.03/0.29 % Model : x86_64 x86_64 0.03/0.29 % CPU : Intel(R) Xeon(R) CPU E5-2609 0 @ 2.40GHz 0.03/0.29 % Memory : 32218.625MB 0.03/0.29 % OS : Linux 3.10.0-693.2.2.el7.x86_64 0.03/0.29 % CPULimit : 300 0.03/0.29 % DateTime : Fri Jul 13 14:52:42 CDT 2018 0.03/0.29 % CPUTime : 0.34/0.60 % SZS status Theorem 0.34/0.60 0.34/0.60 % SZS output start Proof 0.34/0.60 Take the following subset of the input axioms: 0.34/0.60 fof(less_property, axiom, 0.34/0.60 ![X, Y]: (less(X, Y) <=> (X!=Y & ~less(Y, X)))). 0.34/0.60 fof(something_not_n12, conjecture, ?[X]: X!=n12). 0.34/0.60 0.34/0.60 Now clausify the problem and encode Horn clauses using encoding 3 of 0.34/0.60 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.34/0.60 We repeatedly replace C & s=t => u=v by the two clauses: 0.34/0.60 $$fresh(y, y, x1...xn) = u 0.34/0.60 C => $$fresh(s, t, x1...xn) = v 0.34/0.60 where $$fresh is a fresh function symbol and x1..xn are the free 0.34/0.60 variables of u and v. 0.34/0.60 A predicate p(X) is encoded as p(X)=$$true (this is sound, because the 0.34/0.60 input problem has no model of domain size 1). 0.34/0.60 0.34/0.60 The encoding turns the above axioms into the following unit equations and goals: 0.34/0.60 0.34/0.60 Axiom 472 (something_not_n12): X = n12. 0.34/0.60 0.34/0.60 Lemma 473: X = ?. 0.34/0.60 Proof: 0.34/0.60 X 0.34/0.60 = { by axiom 472 (something_not_n12) } 0.34/0.60 n12 0.34/0.60 = { by axiom 472 (something_not_n12) } 0.34/0.60 ? 0.34/0.60 0.34/0.60 Goal 1 (true_equals_false): $$true = $$false. 0.34/0.60 Proof: 0.34/0.60 $$true 0.34/0.60 = { by lemma 473 } 0.34/0.60 ? 0.34/0.60 = { by lemma 473 } 0.34/0.60 $$false 0.34/0.60 % SZS output end Proof 0.34/0.60 0.34/0.60 RESULT: Theorem (the conjecture is true). 0.34/0.61 EOF