0.06/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.06/0.13 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.34 % Computer : n010.cluster.edu 0.12/0.34 % Model : x86_64 x86_64 0.12/0.34 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.12/0.34 % Memory : 8042.1875MB 0.12/0.34 % OS : Linux 3.10.0-693.el7.x86_64 0.12/0.34 % CPULimit : 180 0.12/0.34 % DateTime : Thu Aug 29 11:18:06 EDT 2019 0.12/0.34 % CPUTime : 2.06/2.28 % SZS status Theorem 2.06/2.28 2.06/2.28 % SZS output start Proof 2.06/2.28 Take the following subset of the input axioms: 2.06/2.28 fof(aSatz7_15a, axiom, ![Xa, Xp, Xq, Xr]: (~s_t(Xp, Xq, Xr) | s_t(s(Xa, Xp), s(Xa, Xq), s(Xa, Xr)))). 2.06/2.28 fof(aSatz7_15b, conjecture, ![Xa, Xp, Xq, Xr]: (s_t(Xp, Xq, Xr) | ~s_t(s(Xa, Xp), s(Xa, Xq), s(Xa, Xr)))). 2.06/2.28 fof(aSatz7_7, axiom, ![Xa, Xp]: s(Xa, s(Xa, Xp))=Xp). 2.06/2.28 2.06/2.28 Now clausify the problem and encode Horn clauses using encoding 3 of 2.06/2.28 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 2.06/2.28 We repeatedly replace C & s=t => u=v by the two clauses: 2.06/2.28 fresh(y, y, x1...xn) = u 2.06/2.28 C => fresh(s, t, x1...xn) = v 2.06/2.28 where fresh is a fresh function symbol and x1..xn are the free 2.06/2.28 variables of u and v. 2.06/2.28 A predicate p(X) is encoded as p(X)=true (this is sound, because the 2.06/2.28 input problem has no model of domain size 1). 2.06/2.28 2.06/2.28 The encoding turns the above axioms into the following unit equations and goals: 2.06/2.28 2.06/2.28 Axiom 1 (aSatz7_15a): fresh57(X, X, Y, Z, W, V) = true2. 2.06/2.28 Axiom 2 (aSatz7_15a): fresh57(s_t(X, Y, Z), true2, X, Y, Z, W) = s_t(s(W, X), s(W, Y), s(W, Z)). 2.06/2.28 Axiom 3 (aSatz7_7): s(X, s(X, Y)) = Y. 2.06/2.28 Axiom 4 (aSatz7_15b): s_t(s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp), s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq), s(sK1_aSatz7_15b_Xa, sK2_aSatz7_15b_Xr)) = true2. 2.06/2.28 2.06/2.28 Goal 1 (aSatz7_15b_1): s_t(sK4_aSatz7_15b_Xp, sK3_aSatz7_15b_Xq, sK2_aSatz7_15b_Xr) = true2. 2.06/2.28 Proof: 2.06/2.28 s_t(sK4_aSatz7_15b_Xp, sK3_aSatz7_15b_Xq, sK2_aSatz7_15b_Xr) 2.06/2.28 = { by axiom 3 (aSatz7_7) } 2.06/2.28 s_t(s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp)), sK3_aSatz7_15b_Xq, sK2_aSatz7_15b_Xr) 2.06/2.28 = { by axiom 3 (aSatz7_7) } 2.06/2.28 s_t(s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp)), s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq)), sK2_aSatz7_15b_Xr) 2.06/2.28 = { by axiom 3 (aSatz7_7) } 2.06/2.28 s_t(s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp)), s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq)), s(sK1_aSatz7_15b_Xa, s(sK1_aSatz7_15b_Xa, sK2_aSatz7_15b_Xr))) 2.06/2.28 = { by axiom 2 (aSatz7_15a) } 2.06/2.28 fresh57(s_t(s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp), s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq), s(sK1_aSatz7_15b_Xa, sK2_aSatz7_15b_Xr)), true2, s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp), s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq), s(sK1_aSatz7_15b_Xa, sK2_aSatz7_15b_Xr), sK1_aSatz7_15b_Xa) 2.06/2.28 = { by axiom 4 (aSatz7_15b) } 2.06/2.28 fresh57(true2, true2, s(sK1_aSatz7_15b_Xa, sK4_aSatz7_15b_Xp), s(sK1_aSatz7_15b_Xa, sK3_aSatz7_15b_Xq), s(sK1_aSatz7_15b_Xa, sK2_aSatz7_15b_Xr), sK1_aSatz7_15b_Xa) 2.06/2.28 = { by axiom 1 (aSatz7_15a) } 2.06/2.28 true2 2.06/2.28 % SZS output end Proof 2.06/2.28 2.06/2.28 RESULT: Theorem (the conjecture is true). 2.13/2.29 EOF