0.03/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.03/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.33 % Computer : n010.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 09:07:06 EDT 2019 0.12/0.34 % CPUTime : 0.50/0.70 % SZS status Unsatisfiable 0.50/0.70 0.50/0.70 % SZS output start Proof 0.50/0.70 Take the following subset of the input axioms: 0.50/0.72 fof(axiom_1, axiom, s0(d)=true). 0.50/0.72 fof(axiom_12, axiom, ![X]: true=m0(a, X, a)). 0.50/0.72 fof(axiom_14, axiom, ![X]: p0(b, X)=true). 0.50/0.72 fof(axiom_20, axiom, true=l0(a)). 0.50/0.72 fof(axiom_30, axiom, n0(e, e)=true). 0.50/0.72 fof(ifeq_axiom, axiom, ![C, B, A]: B=ifeq(A, A, B, C)). 0.50/0.72 fof(prove_this, negated_conjecture, r4(b)!=true). 0.50/0.72 fof(rule_002, axiom, ![G, H]: ifeq(n0(H, G), true, l1(G, G), true)=true). 0.50/0.72 fof(rule_023, axiom, true=ifeq(l0(a), true, ifeq(s0(d), true, m1(a, a, a), true), true)). 0.50/0.72 fof(rule_110, axiom, ![C, D, B]: ifeq(m0(C, D, B), true, q1(B, B, B), true)=true). 0.50/0.72 fof(rule_150, axiom, ![F, G]: ifeq(m1(G, G, F), true, p2(F, F, F), true)=true). 0.50/0.72 fof(rule_165, axiom, ![J, A, I]: ifeq(p2(J, J, A), true, ifeq(q1(J, A, J), true, p2(I, I, I), true), true)=true). 0.50/0.72 fof(rule_186, axiom, ![G, H]: true=ifeq(l1(H, G), true, q2(G, G, H), true)). 0.50/0.72 fof(rule_240, axiom, ![E, F, D]: true=ifeq(p2(E, F, D), true, n3(D), true)). 0.50/0.72 fof(rule_255, axiom, ![G, H, I]: ifeq(q2(I, G, H), true, ifeq(n0(I, G), true, q3(G, H), true), true)=true). 0.50/0.72 fof(rule_298, axiom, ![G, H, J, I]: ifeq(q3(H, I), true, ifeq(n3(G), true, ifeq(p0(J, G), true, r4(G), true), true), true)=true). 0.50/0.72 0.50/0.72 Now clausify the problem and encode Horn clauses using encoding 3 of 0.50/0.72 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.50/0.72 We repeatedly replace C & s=t => u=v by the two clauses: 0.50/0.72 fresh(y, y, x1...xn) = u 0.50/0.72 C => fresh(s, t, x1...xn) = v 0.50/0.72 where fresh is a fresh function symbol and x1..xn are the free 0.50/0.72 variables of u and v. 0.50/0.72 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.50/0.72 input problem has no model of domain size 1). 0.50/0.72 0.50/0.72 The encoding turns the above axioms into the following unit equations and goals: 0.50/0.72 0.50/0.72 Axiom 1 (rule_240): true = ifeq(p2(X, Y, Z), true, n3(Z), true). 0.50/0.72 Axiom 2 (rule_165): ifeq(p2(X, X, Y), true, ifeq(q1(X, Y, X), true, p2(Z, Z, Z), true), true) = true. 0.50/0.72 Axiom 3 (rule_255): ifeq(q2(X, Y, Z), true, ifeq(n0(X, Y), true, q3(Y, Z), true), true) = true. 0.50/0.72 Axiom 4 (rule_110): ifeq(m0(X, Y, Z), true, q1(Z, Z, Z), true) = true. 0.50/0.72 Axiom 5 (axiom_20): true = l0(a). 0.50/0.72 Axiom 6 (rule_186): true = ifeq(l1(X, Y), true, q2(Y, Y, X), true). 0.50/0.72 Axiom 7 (rule_150): ifeq(m1(X, X, Y), true, p2(Y, Y, Y), true) = true. 0.50/0.72 Axiom 8 (rule_002): ifeq(n0(X, Y), true, l1(Y, Y), true) = true. 0.50/0.72 Axiom 9 (axiom_14): p0(b, X) = true. 0.50/0.72 Axiom 10 (axiom_1): s0(d) = true. 0.50/0.72 Axiom 11 (rule_298): ifeq(q3(X, Y), true, ifeq(n3(Z), true, ifeq(p0(W, Z), true, r4(Z), true), true), true) = true. 0.50/0.72 Axiom 12 (ifeq_axiom): X = ifeq(Y, Y, X, Z). 0.50/0.72 Axiom 13 (axiom_30): n0(e, e) = true. 0.50/0.72 Axiom 14 (axiom_12): true = m0(a, X, a). 0.56/0.74 Axiom 15 (rule_023): true = ifeq(l0(a), true, ifeq(s0(d), true, m1(a, a, a), true), true). 0.56/0.74 0.56/0.74 Goal 1 (prove_this): r4(b) = true. 0.56/0.74 Proof: 0.56/0.74 r4(b) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(true, true, r4(b), true) 0.56/0.74 = { by axiom 9 (axiom_14) } 0.56/0.74 ifeq(p0(b, b), true, r4(b), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(true, true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 1 (rule_240) } 0.56/0.74 ifeq(ifeq(p2(b, b, b), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(true, true, p2(b, b, b), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 4 (rule_110) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(m0(a, ?, a), true, q1(a, a, a), true), true, p2(b, b, b), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 14 (axiom_12) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(true, true, q1(a, a, a), true), true, p2(b, b, b), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(q1(a, a, a), true, p2(b, b, b), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(true, true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 7 (rule_150) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(m1(a, a, a), true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(ifeq(true, true, m1(a, a, a), true), true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(ifeq(true, true, ifeq(true, true, m1(a, a, a), true), true), true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 5 (axiom_20) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(ifeq(l0(a), true, ifeq(true, true, m1(a, a, a), true), true), true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 10 (axiom_1) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(ifeq(l0(a), true, ifeq(s0(d), true, m1(a, a, a), true), true), true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 15 (rule_023) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(true, true, p2(a, a, a), true), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(p2(a, a, a), true, ifeq(q1(a, a, a), true, p2(b, b, b), true), true), true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 2 (rule_165) } 0.56/0.74 ifeq(ifeq(true, true, n3(b), true), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(true, true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 3 (rule_255) } 0.56/0.74 ifeq(ifeq(q2(e, e, e), true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(true, true, q2(e, e, e), true), true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 8 (rule_002) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(n0(e, e), true, l1(e, e), true), true, q2(e, e, e), true), true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 13 (axiom_30) } 0.56/0.74 ifeq(ifeq(ifeq(ifeq(true, true, l1(e, e), true), true, q2(e, e, e), true), true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(ifeq(l1(e, e), true, q2(e, e, e), true), true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 6 (rule_186) } 0.56/0.74 ifeq(ifeq(true, true, ifeq(n0(e, e), true, q3(e, e), true), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(ifeq(n0(e, e), true, q3(e, e), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 13 (axiom_30) } 0.56/0.74 ifeq(ifeq(true, true, q3(e, e), true), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 12 (ifeq_axiom) } 0.56/0.74 ifeq(q3(e, e), true, ifeq(n3(b), true, ifeq(p0(b, b), true, r4(b), true), true), true) 0.56/0.74 = { by axiom 11 (rule_298) } 0.56/0.74 true 0.56/0.74 % SZS output end Proof 0.56/0.74 0.56/0.74 RESULT: Unsatisfiable (the axioms are contradictory). 0.56/0.75 EOF