0.03/0.11 % 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 : n018.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 09:19:06 EDT 2019 0.12/0.33 % CPUTime : 0.18/0.42 % SZS status Unsatisfiable 0.18/0.42 0.18/0.42 % SZS output start Proof 0.18/0.42 Take the following subset of the input axioms: 0.18/0.42 fof(additive_inverse, axiom, ![X]: add(X, inverse(X))=n1). 0.18/0.42 fof(multiply_add, axiom, ![X, Y]: Y=multiply(add(X, Y), Y)). 0.18/0.42 fof(multiply_add_property, axiom, ![X, Y, Z]: multiply(X, add(Y, Z))=add(multiply(Y, X), multiply(Z, X))). 0.18/0.42 fof(pixley1, axiom, ![X, Y]: pixley(X, X, Y)=Y). 0.18/0.42 fof(pixley2, axiom, ![X, Y]: pixley(X, Y, Y)=X). 0.18/0.42 fof(pixley3, axiom, ![X, Y]: X=pixley(X, Y, X)). 0.18/0.42 fof(pixley_defn, axiom, ![X, Y, Z]: pixley(X, Y, Z)=add(multiply(X, inverse(Y)), add(multiply(X, Z), multiply(inverse(Y), Z)))). 0.18/0.42 fof(prove_equal_identity, negated_conjecture, multiply(b, inverse(b))!=multiply(a, inverse(a))). 0.18/0.42 0.18/0.42 Now clausify the problem and encode Horn clauses using encoding 3 of 0.18/0.42 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.18/0.42 We repeatedly replace C & s=t => u=v by the two clauses: 0.18/0.42 fresh(y, y, x1...xn) = u 0.18/0.42 C => fresh(s, t, x1...xn) = v 0.18/0.42 where fresh is a fresh function symbol and x1..xn are the free 0.18/0.42 variables of u and v. 0.18/0.42 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.18/0.42 input problem has no model of domain size 1). 0.18/0.42 0.18/0.42 The encoding turns the above axioms into the following unit equations and goals: 0.18/0.42 0.18/0.42 Axiom 1 (pixley1): pixley(X, X, Y) = Y. 0.18/0.42 Axiom 2 (pixley2): pixley(X, Y, Y) = X. 0.18/0.42 Axiom 3 (pixley_defn): pixley(X, Y, Z) = add(multiply(X, inverse(Y)), add(multiply(X, Z), multiply(inverse(Y), Z))). 0.18/0.42 Axiom 4 (multiply_add_property): multiply(X, add(Y, Z)) = add(multiply(Y, X), multiply(Z, X)). 0.18/0.42 Axiom 5 (additive_inverse): add(X, inverse(X)) = n1. 0.18/0.42 Axiom 6 (multiply_add): X = multiply(add(Y, X), X). 0.18/0.44 Axiom 7 (pixley3): X = pixley(X, Y, X). 0.18/0.44 0.18/0.44 Lemma 8: multiply(n1, inverse(X)) = inverse(X). 0.18/0.44 Proof: 0.18/0.44 multiply(n1, inverse(X)) 0.18/0.44 = { by axiom 5 (additive_inverse) } 0.18/0.44 multiply(add(X, inverse(X)), inverse(X)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 inverse(X) 0.18/0.44 0.18/0.44 Lemma 9: multiply(X, add(Y, add(Z, X))) = add(multiply(Y, X), X). 0.18/0.44 Proof: 0.18/0.44 multiply(X, add(Y, add(Z, X))) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(multiply(Y, X), multiply(add(Z, X), X)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(multiply(Y, X), X) 0.18/0.44 0.18/0.44 Lemma 10: add(multiply(X, inverse(Y)), multiply(Z, add(X, inverse(Y)))) = pixley(X, Y, Z). 0.18/0.44 Proof: 0.18/0.44 add(multiply(X, inverse(Y)), multiply(Z, add(X, inverse(Y)))) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(multiply(X, inverse(Y)), add(multiply(X, Z), multiply(inverse(Y), Z))) 0.18/0.44 = { by axiom 3 (pixley_defn) } 0.18/0.44 pixley(X, Y, Z) 0.18/0.44 0.18/0.44 Lemma 11: add(multiply(Y, inverse(Y)), multiply(X, n1)) = X. 0.18/0.44 Proof: 0.18/0.44 add(multiply(Y, inverse(Y)), multiply(X, n1)) 0.18/0.44 = { by axiom 5 (additive_inverse) } 0.18/0.44 add(multiply(Y, inverse(Y)), multiply(X, add(Y, inverse(Y)))) 0.18/0.44 = { by lemma 10 } 0.18/0.44 pixley(Y, Y, X) 0.18/0.44 = { by axiom 1 (pixley1) } 0.18/0.44 X 0.18/0.44 0.18/0.44 Lemma 12: add(multiply(X, multiply(Y, n1)), multiply(Y, n1)) = multiply(multiply(Y, n1), add(X, Y)). 0.18/0.44 Proof: 0.18/0.44 add(multiply(X, multiply(Y, n1)), multiply(Y, n1)) 0.18/0.44 = { by lemma 9 } 0.18/0.44 multiply(multiply(Y, n1), add(X, add(multiply(?, inverse(?)), multiply(Y, n1)))) 0.18/0.44 = { by lemma 11 } 0.18/0.44 multiply(multiply(Y, n1), add(X, Y)) 0.18/0.44 0.18/0.44 Lemma 13: multiply(X, add(add(Y, X), Z)) = add(X, multiply(Z, X)). 0.18/0.44 Proof: 0.18/0.44 multiply(X, add(add(Y, X), Z)) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(multiply(add(Y, X), X), multiply(Z, X)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(X, multiply(Z, X)) 0.18/0.44 0.18/0.44 Lemma 14: multiply(inverse(X), add(n1, n1)) = add(inverse(X), inverse(X)). 0.18/0.44 Proof: 0.18/0.44 multiply(inverse(X), add(n1, n1)) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(multiply(n1, inverse(X)), multiply(n1, inverse(X))) 0.18/0.44 = { by lemma 8 } 0.18/0.44 add(inverse(X), multiply(n1, inverse(X))) 0.18/0.44 = { by lemma 8 } 0.18/0.44 add(inverse(X), inverse(X)) 0.18/0.44 0.18/0.44 Lemma 15: multiply(multiply(Y, add(Z, X)), multiply(X, Y)) = multiply(X, Y). 0.18/0.44 Proof: 0.18/0.44 multiply(multiply(Y, add(Z, X)), multiply(X, Y)) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 multiply(add(multiply(Z, Y), multiply(X, Y)), multiply(X, Y)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 multiply(X, Y) 0.18/0.44 0.18/0.44 Lemma 16: add(inverse(n1), multiply(X, n1)) = X. 0.18/0.44 Proof: 0.18/0.44 add(inverse(n1), multiply(X, n1)) 0.18/0.44 = { by lemma 8 } 0.18/0.44 add(multiply(n1, inverse(n1)), multiply(X, n1)) 0.18/0.44 = { by axiom 5 (additive_inverse) } 0.18/0.44 add(multiply(n1, inverse(n1)), multiply(X, add(n1, inverse(n1)))) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(multiply(n1, inverse(n1)), add(multiply(n1, X), multiply(inverse(n1), X))) 0.18/0.44 = { by axiom 3 (pixley_defn) } 0.18/0.44 pixley(n1, n1, X) 0.18/0.44 = { by axiom 1 (pixley1) } 0.18/0.44 X 0.18/0.44 0.18/0.44 Lemma 17: add(X, n1) = add(?, n1). 0.18/0.44 Proof: 0.18/0.44 add(X, n1) 0.18/0.44 = { by lemma 16 } 0.18/0.44 add(inverse(n1), multiply(add(X, n1), n1)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(inverse(n1), n1) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(inverse(n1), multiply(add(?, n1), n1)) 0.18/0.44 = { by lemma 16 } 0.18/0.44 add(?, n1) 0.18/0.44 0.18/0.44 Lemma 18: multiply(n1, add(inverse(X), inverse(X))) = multiply(inverse(X), add(?, n1)). 0.18/0.44 Proof: 0.18/0.44 multiply(n1, add(inverse(X), inverse(X))) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 multiply(multiply(add(n1, n1), n1), add(inverse(X), inverse(X))) 0.18/0.44 = { by axiom 5 (additive_inverse) } 0.18/0.44 multiply(multiply(add(n1, n1), add(X, inverse(X))), add(inverse(X), inverse(X))) 0.18/0.44 = { by lemma 14 } 0.18/0.44 multiply(multiply(add(n1, n1), add(X, inverse(X))), multiply(inverse(X), add(n1, n1))) 0.18/0.44 = { by lemma 15 } 0.18/0.44 multiply(inverse(X), add(n1, n1)) 0.18/0.44 = { by lemma 17 } 0.18/0.44 multiply(inverse(X), add(?, n1)) 0.18/0.44 0.18/0.44 Lemma 19: multiply(inverse(X), add(?, n1)) = add(inverse(X), inverse(X)). 0.18/0.44 Proof: 0.18/0.44 multiply(inverse(X), add(?, n1)) 0.18/0.44 = { by lemma 18 } 0.18/0.44 multiply(n1, add(inverse(X), inverse(X))) 0.18/0.44 = { by axiom 5 (additive_inverse) } 0.18/0.44 multiply(add(X, inverse(X)), add(inverse(X), inverse(X))) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 multiply(multiply(add(add(?, inverse(X)), add(X, inverse(X))), add(X, inverse(X))), add(inverse(X), inverse(X))) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 multiply(multiply(add(add(?, inverse(X)), add(X, inverse(X))), add(X, inverse(X))), add(multiply(add(?, inverse(X)), inverse(X)), inverse(X))) 0.18/0.44 = { by lemma 9 } 0.18/0.44 multiply(multiply(add(add(?, inverse(X)), add(X, inverse(X))), add(X, inverse(X))), multiply(inverse(X), add(add(?, inverse(X)), add(X, inverse(X))))) 0.18/0.44 = { by lemma 15 } 0.18/0.44 multiply(inverse(X), add(add(?, inverse(X)), add(X, inverse(X)))) 0.18/0.44 = { by lemma 9 } 0.18/0.44 add(multiply(add(?, inverse(X)), inverse(X)), inverse(X)) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(inverse(X), inverse(X)) 0.18/0.44 0.18/0.44 Lemma 20: add(inverse(n1), add(inverse(X), inverse(X))) = multiply(inverse(X), n1). 0.18/0.44 Proof: 0.18/0.44 add(inverse(n1), add(inverse(X), inverse(X))) 0.18/0.44 = { by lemma 19 } 0.18/0.44 add(inverse(n1), multiply(inverse(X), add(?, n1))) 0.18/0.44 = { by lemma 18 } 0.18/0.44 add(inverse(n1), multiply(n1, add(inverse(X), inverse(X)))) 0.18/0.44 = { by axiom 4 (multiply_add_property) } 0.18/0.44 add(inverse(n1), add(multiply(inverse(X), n1), multiply(inverse(X), n1))) 0.18/0.44 = { by axiom 6 (multiply_add) } 0.18/0.44 add(inverse(n1), add(multiply(add(?, multiply(inverse(X), n1)), multiply(inverse(X), n1)), multiply(inverse(X), n1))) 0.18/0.44 = { by lemma 12 } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), add(add(?, multiply(inverse(X), n1)), inverse(X)))) 0.18/0.44 = { by lemma 13 } 0.18/0.44 add(inverse(n1), add(multiply(inverse(X), n1), multiply(inverse(X), multiply(inverse(X), n1)))) 0.18/0.44 = { by lemma 13 } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), add(add(multiply(?, inverse(?)), multiply(inverse(X), n1)), inverse(X)))) 0.18/0.44 = { by lemma 11 } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), add(inverse(X), inverse(X)))) 0.18/0.44 = { by lemma 12 } 0.18/0.44 add(inverse(n1), add(multiply(inverse(X), multiply(inverse(X), n1)), multiply(inverse(X), n1))) 0.18/0.44 = { by lemma 8 } 0.18/0.44 add(inverse(n1), add(multiply(multiply(n1, inverse(X)), multiply(inverse(X), n1)), multiply(inverse(X), n1))) 0.18/0.44 = { by lemma 9 } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), add(multiply(n1, inverse(X)), add(multiply(n1, n1), multiply(inverse(X), n1))))) 0.18/0.44 = { by axiom 3 (pixley_defn) } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), pixley(n1, X, n1))) 0.18/0.44 = { by axiom 7 (pixley3) } 0.18/0.44 add(inverse(n1), multiply(multiply(inverse(X), n1), n1)) 0.18/0.44 = { by lemma 16 } 0.18/0.45 multiply(inverse(X), n1) 0.18/0.45 0.18/0.45 Lemma 21: add(inverse(n1), n1) = add(?, n1). 0.18/0.45 Proof: 0.18/0.45 add(inverse(n1), n1) 0.18/0.45 = { by axiom 6 (multiply_add) } 0.18/0.45 add(inverse(n1), multiply(add(?, n1), n1)) 0.18/0.45 = { by lemma 16 } 0.18/0.45 add(?, n1) 0.18/0.45 0.18/0.45 Lemma 22: add(multiply(Y, inverse(X)), inverse(X)) = multiply(inverse(X), add(Y, n1)). 0.18/0.45 Proof: 0.18/0.45 add(multiply(Y, inverse(X)), inverse(X)) 0.18/0.45 = { by lemma 8 } 0.18/0.45 add(multiply(Y, inverse(X)), multiply(n1, inverse(X))) 0.18/0.45 = { by axiom 4 (multiply_add_property) } 0.18/0.45 multiply(inverse(X), add(Y, n1)) 0.18/0.45 0.18/0.45 Lemma 23: multiply(inverse(X), add(?, n1)) = multiply(inverse(X), n1). 0.18/0.45 Proof: 0.18/0.45 multiply(inverse(X), add(?, n1)) 0.18/0.45 = { by lemma 21 } 0.18/0.45 multiply(inverse(X), add(inverse(n1), n1)) 0.18/0.45 = { by lemma 22 } 0.18/0.45 add(multiply(inverse(n1), inverse(X)), inverse(X)) 0.18/0.45 = { by lemma 9 } 0.18/0.45 multiply(inverse(X), add(inverse(n1), add(inverse(X), inverse(X)))) 0.18/0.45 = { by lemma 16 } 0.18/0.45 multiply(add(inverse(n1), multiply(inverse(X), n1)), add(inverse(n1), add(inverse(X), inverse(X)))) 0.18/0.45 = { by lemma 20 } 0.18/0.45 multiply(add(inverse(n1), multiply(inverse(X), n1)), multiply(inverse(X), n1)) 0.18/0.45 = { by axiom 6 (multiply_add) } 0.18/0.45 multiply(inverse(X), n1) 0.18/0.45 0.18/0.45 Lemma 24: add(inverse(X), inverse(X)) = multiply(inverse(X), n1). 0.18/0.45 Proof: 0.18/0.45 add(inverse(X), inverse(X)) 0.18/0.45 = { by lemma 19 } 0.18/0.45 multiply(inverse(X), add(?, n1)) 0.18/0.45 = { by lemma 23 } 0.18/0.45 multiply(inverse(X), n1) 0.18/0.45 0.18/0.45 Lemma 25: multiply(inverse(X), n1) = inverse(X). 0.18/0.45 Proof: 0.18/0.45 multiply(inverse(X), n1) 0.18/0.45 = { by lemma 20 } 0.18/0.45 add(inverse(n1), add(inverse(X), inverse(X))) 0.18/0.45 = { by lemma 24 } 0.18/0.45 add(inverse(n1), multiply(inverse(X), n1)) 0.18/0.45 = { by lemma 16 } 0.18/0.45 inverse(X) 0.18/0.45 0.18/0.45 Lemma 26: add(inverse(n1), inverse(X)) = inverse(X). 0.18/0.45 Proof: 0.18/0.45 add(inverse(n1), inverse(X)) 0.18/0.45 = { by lemma 25 } 0.18/0.45 add(inverse(n1), multiply(inverse(X), n1)) 0.18/0.45 = { by lemma 16 } 0.18/0.46 inverse(X) 0.18/0.46 0.18/0.46 Lemma 27: multiply(X, inverse(X)) = inverse(n1). 0.18/0.46 Proof: 0.18/0.46 multiply(X, inverse(X)) 0.18/0.46 = { by lemma 26 } 0.18/0.46 multiply(X, add(inverse(n1), inverse(X))) 0.18/0.46 = { by axiom 4 (multiply_add_property) } 0.18/0.46 add(multiply(inverse(n1), X), multiply(inverse(X), X)) 0.18/0.46 = { by axiom 6 (multiply_add) } 0.18/0.46 multiply(add(multiply(inverse(n1), inverse(X)), add(multiply(inverse(n1), X), multiply(inverse(X), X))), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by axiom 3 (pixley_defn) } 0.18/0.46 multiply(pixley(inverse(n1), X, X), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by axiom 2 (pixley2) } 0.18/0.46 multiply(inverse(n1), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by lemma 25 } 0.18/0.46 multiply(multiply(inverse(n1), n1), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by lemma 24 } 0.18/0.46 multiply(add(inverse(n1), inverse(n1)), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by lemma 14 } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(inverse(n1), X), multiply(inverse(X), X))) 0.18/0.46 = { by axiom 4 (multiply_add_property) } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), multiply(X, add(inverse(n1), inverse(X)))) 0.18/0.46 = { by axiom 2 (pixley2) } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), pixley(multiply(X, add(inverse(n1), inverse(X))), n1, n1)) 0.18/0.46 = { by lemma 10 } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(n1, add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by axiom 5 (additive_inverse) } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(add(inverse(n1), inverse(inverse(n1))), add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by lemma 26 } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(add(inverse(n1), add(inverse(n1), inverse(inverse(n1)))), add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by axiom 5 (additive_inverse) } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(add(inverse(n1), n1), add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by lemma 21 } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(add(?, n1), add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by lemma 17 } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(add(n1, n1), add(multiply(X, add(inverse(n1), inverse(X))), inverse(n1))))) 0.18/0.46 = { by axiom 4 (multiply_add_property) } 0.18/0.46 multiply(multiply(inverse(n1), add(n1, n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), add(multiply(multiply(X, add(inverse(n1), inverse(X))), add(n1, n1)), multiply(inverse(n1), add(n1, n1))))) 0.18/0.46 = { by lemma 9 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(inverse(n1), add(n1, n1))), multiply(inverse(n1), add(n1, n1))) 0.18/0.46 = { by lemma 17 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(inverse(n1), add(?, n1))), multiply(inverse(n1), add(n1, n1))) 0.18/0.46 = { by lemma 23 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), multiply(inverse(n1), n1)), multiply(inverse(n1), add(n1, n1))) 0.18/0.46 = { by lemma 25 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), inverse(n1)), multiply(inverse(n1), add(n1, n1))) 0.18/0.46 = { by lemma 17 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), inverse(n1)), multiply(inverse(n1), add(?, n1))) 0.18/0.46 = { by lemma 23 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), inverse(n1)), multiply(inverse(n1), n1)) 0.18/0.46 = { by lemma 25 } 0.18/0.46 add(multiply(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), inverse(n1)), inverse(n1)) 0.18/0.46 = { by lemma 22 } 0.18/0.46 multiply(inverse(n1), add(multiply(multiply(X, add(inverse(n1), inverse(X))), inverse(n1)), n1)) 0.18/0.46 = { by lemma 17 } 0.18/0.46 multiply(inverse(n1), add(?, n1)) 0.18/0.46 = { by lemma 23 } 0.18/0.46 multiply(inverse(n1), n1) 0.18/0.46 = { by lemma 25 } 0.18/0.46 inverse(n1) 0.18/0.46 0.18/0.46 Goal 1 (prove_equal_identity): multiply(b, inverse(b)) = multiply(a, inverse(a)). 0.18/0.46 Proof: 0.18/0.46 multiply(b, inverse(b)) 0.18/0.46 = { by lemma 27 } 0.18/0.46 inverse(n1) 0.18/0.46 = { by lemma 27 } 0.18/0.46 multiply(a, inverse(a)) 0.18/0.46 % SZS output end Proof 0.18/0.46 0.18/0.46 RESULT: Unsatisfiable (the axioms are contradictory). 0.18/0.46 EOF