0.08/0.10 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.08/0.11 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.11/0.31 % Computer : n031.cluster.edu 0.11/0.31 % Model : x86_64 x86_64 0.11/0.31 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.11/0.31 % Memory : 8042.1875MB 0.11/0.31 % OS : Linux 3.10.0-693.el7.x86_64 0.11/0.31 % CPULimit : 960 0.11/0.31 % WCLimit : 120 0.11/0.31 % DateTime : Thu Jul 2 07:26:02 EDT 2020 0.11/0.31 % CPUTime : 0.16/0.36 % SZS status Theorem 0.16/0.36 0.16/0.36 % SZS output start Proof 0.16/0.36 Take the following subset of the input axioms: 0.16/0.37 fof(axiom_1, axiom, ![B, C, A]: times(times(A, B), C)=times(B, times(C, A))). 0.16/0.37 fof(axiom_2, axiom, ![B]: (element(B) <=> ?[C]: (times(B, C)=B & times(B, B)=C))). 0.16/0.37 fof(conjecture_1, conjecture, ![B, C, A]: (element(C) <= (element(A) & (times(A, B)=C & element(B))))). 0.16/0.37 0.16/0.37 Now clausify the problem and encode Horn clauses using encoding 3 of 0.16/0.37 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.16/0.37 We repeatedly replace C & s=t => u=v by the two clauses: 0.16/0.37 fresh(y, y, x1...xn) = u 0.16/0.37 C => fresh(s, t, x1...xn) = v 0.16/0.37 where fresh is a fresh function symbol and x1..xn are the free 0.16/0.37 variables of u and v. 0.16/0.37 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.16/0.37 input problem has no model of domain size 1). 0.16/0.37 0.16/0.37 The encoding turns the above axioms into the following unit equations and goals: 0.16/0.37 0.16/0.37 Axiom 1 (axiom_2): fresh3(X, X, Y, Z) = element(Y). 0.16/0.37 Axiom 2 (axiom_2): fresh4(X, X, Y) = true. 0.16/0.37 Axiom 3 (axiom_2_1): fresh(X, X, Y) = Y. 0.16/0.37 Axiom 4 (axiom_2_2): fresh2(X, X, Y) = sK1_axiom_2_C(Y). 0.16/0.37 Axiom 5 (axiom_1): times(times(X, Y), Z) = times(Y, times(Z, X)). 0.16/0.37 Axiom 6 (axiom_2_2): fresh2(element(X), true, X) = times(X, X). 0.16/0.37 Axiom 7 (axiom_2_1): fresh(element(X), true, X) = times(X, sK1_axiom_2_C(X)). 0.16/0.37 Axiom 8 (axiom_2): fresh3(times(X, X), Y, X, Y) = fresh4(times(X, Y), X, X). 0.16/0.37 Axiom 9 (conjecture_1): times(sK2_conjecture_1_A, sK4_conjecture_1_B) = sK3_conjecture_1_C. 0.16/0.37 Axiom 10 (conjecture_1_1): element(sK4_conjecture_1_B) = true. 0.16/0.37 Axiom 11 (conjecture_1_2): element(sK2_conjecture_1_A) = true. 0.16/0.37 0.16/0.37 Lemma 12: times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(Y, X))) = times(Y, times(X, sK3_conjecture_1_C)). 0.16/0.37 Proof: 0.16/0.37 times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(Y, X))) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(sK2_conjecture_1_A, times(times(X, sK4_conjecture_1_B), Y)) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(times(Y, sK2_conjecture_1_A), times(X, sK4_conjecture_1_B)) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(times(sK4_conjecture_1_B, times(Y, sK2_conjecture_1_A)), X) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(times(times(sK2_conjecture_1_A, sK4_conjecture_1_B), Y), X) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(Y, times(X, times(sK2_conjecture_1_A, sK4_conjecture_1_B))) 0.16/0.37 = { by axiom 9 (conjecture_1) } 0.16/0.37 times(Y, times(X, sK3_conjecture_1_C)) 0.16/0.37 0.16/0.37 Lemma 13: times(sK4_conjecture_1_B, sK4_conjecture_1_B) = sK1_axiom_2_C(sK4_conjecture_1_B). 0.16/0.37 Proof: 0.16/0.37 times(sK4_conjecture_1_B, sK4_conjecture_1_B) 0.16/0.37 = { by axiom 6 (axiom_2_2) } 0.16/0.37 fresh2(element(sK4_conjecture_1_B), true, sK4_conjecture_1_B) 0.16/0.37 = { by axiom 10 (conjecture_1_1) } 0.16/0.37 fresh2(true, true, sK4_conjecture_1_B) 0.16/0.37 = { by axiom 4 (axiom_2_2) } 0.16/0.37 sK1_axiom_2_C(sK4_conjecture_1_B) 0.16/0.37 0.16/0.37 Lemma 14: times(sK4_conjecture_1_B, sK1_axiom_2_C(sK4_conjecture_1_B)) = sK4_conjecture_1_B. 0.16/0.37 Proof: 0.16/0.37 times(sK4_conjecture_1_B, sK1_axiom_2_C(sK4_conjecture_1_B)) 0.16/0.37 = { by axiom 7 (axiom_2_1) } 0.16/0.37 fresh(element(sK4_conjecture_1_B), true, sK4_conjecture_1_B) 0.16/0.37 = { by axiom 10 (conjecture_1_1) } 0.16/0.37 fresh(true, true, sK4_conjecture_1_B) 0.16/0.37 = { by axiom 3 (axiom_2_1) } 0.16/0.37 sK4_conjecture_1_B 0.16/0.37 0.16/0.37 Lemma 15: times(sK1_axiom_2_C(sK4_conjecture_1_B), sK3_conjecture_1_C) = times(sK4_conjecture_1_B, sK2_conjecture_1_A). 0.16/0.37 Proof: 0.16/0.37 times(sK1_axiom_2_C(sK4_conjecture_1_B), sK3_conjecture_1_C) 0.16/0.37 = { by axiom 9 (conjecture_1) } 0.16/0.37 times(sK1_axiom_2_C(sK4_conjecture_1_B), times(sK2_conjecture_1_A, sK4_conjecture_1_B)) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(times(sK4_conjecture_1_B, sK1_axiom_2_C(sK4_conjecture_1_B)), sK2_conjecture_1_A) 0.16/0.37 = { by lemma 14 } 0.16/0.37 times(sK4_conjecture_1_B, sK2_conjecture_1_A) 0.16/0.37 0.16/0.37 Lemma 16: times(sK4_conjecture_1_B, times(X, sK2_conjecture_1_A)) = times(sK3_conjecture_1_C, X). 0.16/0.37 Proof: 0.16/0.37 times(sK4_conjecture_1_B, times(X, sK2_conjecture_1_A)) 0.16/0.37 = { by axiom 5 (axiom_1) } 0.16/0.37 times(times(sK2_conjecture_1_A, sK4_conjecture_1_B), X) 0.16/0.37 = { by axiom 9 (conjecture_1) } 0.16/0.37 times(sK3_conjecture_1_C, X) 0.16/0.37 0.16/0.37 Lemma 17: times(sK4_conjecture_1_B, times(X, sK4_conjecture_1_B)) = times(sK1_axiom_2_C(sK4_conjecture_1_B), X). 0.16/0.37 Proof: 0.16/0.37 times(sK4_conjecture_1_B, times(X, sK4_conjecture_1_B)) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(times(sK4_conjecture_1_B, sK4_conjecture_1_B), X) 0.16/0.38 = { by lemma 13 } 0.16/0.38 times(sK1_axiom_2_C(sK4_conjecture_1_B), X) 0.16/0.38 0.16/0.38 Lemma 18: times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK3_conjecture_1_C)) = times(sK3_conjecture_1_C, sK1_axiom_2_C(sK4_conjecture_1_B)). 0.16/0.38 Proof: 0.16/0.38 times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK3_conjecture_1_C)) 0.16/0.38 = { by axiom 9 (conjecture_1) } 0.16/0.38 times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, times(sK2_conjecture_1_A, sK4_conjecture_1_B))) 0.16/0.38 = { by lemma 17 } 0.16/0.38 times(sK4_conjecture_1_B, times(sK1_axiom_2_C(sK4_conjecture_1_B), sK2_conjecture_1_A)) 0.16/0.38 = { by lemma 16 } 0.16/0.38 times(sK3_conjecture_1_C, sK1_axiom_2_C(sK4_conjecture_1_B)) 0.16/0.38 0.16/0.38 Lemma 19: times(sK2_conjecture_1_A, sK1_axiom_2_C(sK2_conjecture_1_A)) = sK2_conjecture_1_A. 0.16/0.38 Proof: 0.16/0.38 times(sK2_conjecture_1_A, sK1_axiom_2_C(sK2_conjecture_1_A)) 0.16/0.38 = { by axiom 7 (axiom_2_1) } 0.16/0.38 fresh(element(sK2_conjecture_1_A), true, sK2_conjecture_1_A) 0.16/0.38 = { by axiom 11 (conjecture_1_2) } 0.16/0.38 fresh(true, true, sK2_conjecture_1_A) 0.16/0.38 = { by axiom 3 (axiom_2_1) } 0.16/0.38 sK2_conjecture_1_A 0.16/0.38 0.16/0.38 Lemma 20: times(sK3_conjecture_1_C, times(sK1_axiom_2_C(sK2_conjecture_1_A), X)) = times(sK3_conjecture_1_C, X). 0.16/0.38 Proof: 0.16/0.38 times(sK3_conjecture_1_C, times(sK1_axiom_2_C(sK2_conjecture_1_A), X)) 0.16/0.38 = { by lemma 16 } 0.16/0.38 times(sK4_conjecture_1_B, times(times(sK1_axiom_2_C(sK2_conjecture_1_A), X), sK2_conjecture_1_A)) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(sK4_conjecture_1_B, times(X, times(sK2_conjecture_1_A, sK1_axiom_2_C(sK2_conjecture_1_A)))) 0.16/0.38 = { by lemma 19 } 0.16/0.38 times(sK4_conjecture_1_B, times(X, sK2_conjecture_1_A)) 0.16/0.38 = { by lemma 16 } 0.16/0.38 times(sK3_conjecture_1_C, X) 0.16/0.38 0.16/0.38 Lemma 21: times(sK4_conjecture_1_B, sK2_conjecture_1_A) = sK3_conjecture_1_C. 0.16/0.38 Proof: 0.16/0.38 times(sK4_conjecture_1_B, sK2_conjecture_1_A) 0.16/0.38 = { by lemma 15 } 0.16/0.38 times(sK1_axiom_2_C(sK4_conjecture_1_B), sK3_conjecture_1_C) 0.16/0.38 = { by lemma 17 } 0.16/0.38 times(sK4_conjecture_1_B, times(sK3_conjecture_1_C, sK4_conjecture_1_B)) 0.16/0.38 = { by lemma 20 } 0.16/0.38 times(sK4_conjecture_1_B, times(sK3_conjecture_1_C, times(sK1_axiom_2_C(sK2_conjecture_1_A), sK4_conjecture_1_B))) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(sK4_conjecture_1_B, times(times(sK4_conjecture_1_B, sK3_conjecture_1_C), sK1_axiom_2_C(sK2_conjecture_1_A))) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(times(sK1_axiom_2_C(sK2_conjecture_1_A), sK4_conjecture_1_B), times(sK4_conjecture_1_B, sK3_conjecture_1_C)) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(times(sK3_conjecture_1_C, times(sK1_axiom_2_C(sK2_conjecture_1_A), sK4_conjecture_1_B)), sK4_conjecture_1_B) 0.16/0.38 = { by lemma 20 } 0.16/0.38 times(times(sK3_conjecture_1_C, sK4_conjecture_1_B), sK4_conjecture_1_B) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK3_conjecture_1_C)) 0.16/0.38 = { by lemma 12 } 0.16/0.38 times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK4_conjecture_1_B))) 0.16/0.38 = { by lemma 13 } 0.16/0.38 times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, sK1_axiom_2_C(sK4_conjecture_1_B))) 0.16/0.38 = { by lemma 14 } 0.16/0.38 times(sK2_conjecture_1_A, sK4_conjecture_1_B) 0.16/0.38 = { by axiom 9 (conjecture_1) } 0.16/0.38 sK3_conjecture_1_C 0.16/0.38 0.16/0.38 Lemma 22: times(sK2_conjecture_1_A, times(X, sK2_conjecture_1_A)) = times(sK1_axiom_2_C(sK2_conjecture_1_A), X). 0.16/0.38 Proof: 0.16/0.38 times(sK2_conjecture_1_A, times(X, sK2_conjecture_1_A)) 0.16/0.38 = { by axiom 5 (axiom_1) } 0.16/0.38 times(times(sK2_conjecture_1_A, sK2_conjecture_1_A), X) 0.16/0.38 = { by axiom 6 (axiom_2_2) } 0.16/0.38 times(fresh2(element(sK2_conjecture_1_A), true, sK2_conjecture_1_A), X) 0.16/0.38 = { by axiom 11 (conjecture_1_2) } 0.16/0.38 times(fresh2(true, true, sK2_conjecture_1_A), X) 0.16/0.38 = { by axiom 4 (axiom_2_2) } 0.16/0.39 times(sK1_axiom_2_C(sK2_conjecture_1_A), X) 0.16/0.39 0.16/0.39 Goal 1 (conjecture_1_3): element(sK3_conjecture_1_C) = true. 0.16/0.39 Proof: 0.16/0.39 element(sK3_conjecture_1_C) 0.16/0.39 = { by axiom 1 (axiom_2) } 0.16/0.39 fresh3(times(sK3_conjecture_1_C, sK3_conjecture_1_C), times(sK3_conjecture_1_C, sK3_conjecture_1_C), sK3_conjecture_1_C, times(sK3_conjecture_1_C, sK3_conjecture_1_C)) 0.16/0.39 = { by axiom 8 (axiom_2) } 0.16/0.39 fresh4(times(sK3_conjecture_1_C, times(sK3_conjecture_1_C, sK3_conjecture_1_C)), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 12 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK3_conjecture_1_C, sK3_conjecture_1_C))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 12 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK3_conjecture_1_C)))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 21 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK2_conjecture_1_A))))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 15 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, times(sK1_axiom_2_C(sK4_conjecture_1_B), sK3_conjecture_1_C))))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 12 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK4_conjecture_1_B, sK1_axiom_2_C(sK4_conjecture_1_B))))))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 14 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, sK4_conjecture_1_B))))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 13 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, times(sK2_conjecture_1_A, sK1_axiom_2_C(sK4_conjecture_1_B))))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 12 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK1_axiom_2_C(sK4_conjecture_1_B), sK3_conjecture_1_C))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 15 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK4_conjecture_1_B, sK2_conjecture_1_A))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 21 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, sK3_conjecture_1_C)), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by axiom 9 (conjecture_1) } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, times(sK2_conjecture_1_A, sK4_conjecture_1_B))), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by axiom 5 (axiom_1) } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(times(sK4_conjecture_1_B, sK2_conjecture_1_A), sK2_conjecture_1_A)), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 21 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, times(sK3_conjecture_1_C, sK2_conjecture_1_A)), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 22 } 0.16/0.39 fresh4(times(sK1_axiom_2_C(sK2_conjecture_1_A), sK3_conjecture_1_C), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 21 } 0.16/0.39 fresh4(times(sK1_axiom_2_C(sK2_conjecture_1_A), times(sK4_conjecture_1_B, sK2_conjecture_1_A)), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by axiom 5 (axiom_1) } 0.16/0.39 fresh4(times(times(sK2_conjecture_1_A, sK1_axiom_2_C(sK2_conjecture_1_A)), sK4_conjecture_1_B), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by lemma 19 } 0.16/0.39 fresh4(times(sK2_conjecture_1_A, sK4_conjecture_1_B), sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by axiom 9 (conjecture_1) } 0.16/0.39 fresh4(sK3_conjecture_1_C, sK3_conjecture_1_C, sK3_conjecture_1_C) 0.16/0.39 = { by axiom 2 (axiom_2) } 0.16/0.39 true 0.16/0.39 % SZS output end Proof 0.16/0.39 0.16/0.39 RESULT: Theorem (the conjecture is true). 0.20/0.40 EOF