0.11/0.12 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.11/0.12 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.12/0.33 % Computer : n017.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 11:40:19 EDT 2019 0.12/0.33 % CPUTime : 0.56/0.73 % SZS status Unsatisfiable 0.56/0.73 0.56/0.73 % SZS output start Proof 0.56/0.73 Take the following subset of the input axioms: 0.56/0.73 fof(c01, axiom, ![A, B]: B=mult(A, ld(A, B))). 0.56/0.73 fof(c02, axiom, ![A, B]: B=ld(A, mult(A, B))). 0.56/0.73 fof(c06, axiom, ![A]: mult(unit, A)=A). 0.56/0.73 fof(c08, axiom, ![A, B, C]: mult(mult(A, mult(B, mult(B, C))), B)=mult(mult(A, B), mult(B, mult(C, B)))). 0.56/0.73 fof(goals, negated_conjecture, mult(mult(a, c), ld(c, mult(b, c)))!=mult(mult(a, b), c)). 0.56/0.73 0.56/0.73 Now clausify the problem and encode Horn clauses using encoding 3 of 0.56/0.73 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.56/0.73 We repeatedly replace C & s=t => u=v by the two clauses: 0.56/0.73 fresh(y, y, x1...xn) = u 0.56/0.73 C => fresh(s, t, x1...xn) = v 0.56/0.73 where fresh is a fresh function symbol and x1..xn are the free 0.56/0.73 variables of u and v. 0.56/0.73 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.56/0.73 input problem has no model of domain size 1). 0.56/0.73 0.56/0.73 The encoding turns the above axioms into the following unit equations and goals: 0.56/0.73 0.56/0.73 Axiom 1 (c01): X = mult(Y, ld(Y, X)). 0.56/0.73 Axiom 2 (c02): X = ld(Y, mult(Y, X)). 0.56/0.73 Axiom 3 (c06): mult(unit, X) = X. 0.56/0.73 Axiom 4 (c08): mult(mult(X, mult(Y, mult(Y, Z))), Y) = mult(mult(X, Y), mult(Y, mult(Z, Y))). 0.56/0.73 0.56/0.73 Goal 1 (goals): mult(mult(a, c), ld(c, mult(b, c))) = mult(mult(a, b), c). 0.56/0.73 Proof: 0.56/0.73 mult(mult(a, c), ld(c, mult(b, c))) 0.56/0.73 = { by axiom 1 (c01) } 0.56/0.73 mult(mult(a, c), ld(c, mult(mult(c, ld(c, b)), c))) 0.56/0.73 = { by axiom 1 (c01) } 0.56/0.73 mult(mult(a, c), ld(c, mult(mult(c, mult(c, ld(c, ld(c, b)))), c))) 0.56/0.73 = { by axiom 3 (c06) } 0.56/0.73 mult(mult(a, c), ld(c, mult(mult(unit, mult(c, mult(c, ld(c, ld(c, b))))), c))) 0.56/0.73 = { by axiom 4 (c08) } 0.56/0.73 mult(mult(a, c), ld(c, mult(mult(unit, c), mult(c, mult(ld(c, ld(c, b)), c))))) 0.56/0.73 = { by axiom 3 (c06) } 0.56/0.73 mult(mult(a, c), ld(c, mult(c, mult(c, mult(ld(c, ld(c, b)), c))))) 0.56/0.73 = { by axiom 2 (c02) } 0.56/0.73 mult(mult(a, c), mult(c, mult(ld(c, ld(c, b)), c))) 0.56/0.73 = { by axiom 4 (c08) } 0.56/0.73 mult(mult(a, mult(c, mult(c, ld(c, ld(c, b))))), c) 0.56/0.73 = { by axiom 1 (c01) } 0.56/0.73 mult(mult(a, mult(c, ld(c, b))), c) 0.56/0.73 = { by axiom 1 (c01) } 0.56/0.73 mult(mult(a, b), c) 0.56/0.73 % SZS output end Proof 0.56/0.73 0.56/0.73 RESULT: Unsatisfiable (the axioms are contradictory). 0.56/0.73 EOF