0.08/0.13 % Problem : theBenchmark.p : TPTP v0.0.0. Released v0.0.0. 0.08/0.14 % Command : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn 0.14/0.35 % Computer : n014.cluster.edu 0.14/0.35 % Model : x86_64 x86_64 0.14/0.35 % CPU : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz 0.14/0.35 % Memory : 8042.1875MB 0.14/0.35 % OS : Linux 3.10.0-693.el7.x86_64 0.14/0.35 % CPULimit : 180 0.14/0.35 % DateTime : Thu Aug 29 12:59:54 EDT 2019 0.14/0.35 % CPUTime : 0.20/0.55 % SZS status Unsatisfiable 0.20/0.55 0.20/0.55 % SZS output start Proof 0.20/0.55 Take the following subset of the input axioms: 0.20/0.55 fof(f01, axiom, ![B, A]: B=mult(A, ld(A, B))). 0.20/0.55 fof(f02, axiom, ![B, A]: B=ld(A, mult(A, B))). 0.20/0.55 fof(f03, axiom, ![B, A]: A=mult(rd(A, B), B)). 0.20/0.55 fof(f04, axiom, ![B, A]: rd(mult(A, B), B)=A). 0.20/0.55 fof(f05, axiom, ![B, A, C]: mult(mult(A, mult(A, A)), mult(B, C))=mult(mult(A, B), mult(mult(A, A), C))). 0.20/0.55 fof(f06, axiom, ![B, A, C]: mult(mult(A, B), mult(C, C))=mult(mult(A, C), mult(B, C))). 0.20/0.55 fof(goals, negated_conjecture, mult(mult(a, b), mult(a, c))!=mult(mult(a, a), mult(b, c))). 0.20/0.55 0.20/0.55 Now clausify the problem and encode Horn clauses using encoding 3 of 0.20/0.55 http://www.cse.chalmers.se/~nicsma/papers/horn.pdf. 0.20/0.55 We repeatedly replace C & s=t => u=v by the two clauses: 0.20/0.55 fresh(y, y, x1...xn) = u 0.20/0.55 C => fresh(s, t, x1...xn) = v 0.20/0.55 where fresh is a fresh function symbol and x1..xn are the free 0.20/0.55 variables of u and v. 0.20/0.55 A predicate p(X) is encoded as p(X)=true (this is sound, because the 0.20/0.55 input problem has no model of domain size 1). 0.20/0.55 0.20/0.55 The encoding turns the above axioms into the following unit equations and goals: 0.20/0.55 0.20/0.55 Axiom 1 (f06): mult(mult(X, Y), mult(Z, Z)) = mult(mult(X, Z), mult(Y, Z)). 0.20/0.55 Axiom 2 (f02): X = ld(Y, mult(Y, X)). 0.20/0.55 Axiom 3 (f05): mult(mult(X, mult(X, X)), mult(Y, Z)) = mult(mult(X, Y), mult(mult(X, X), Z)). 0.20/0.55 Axiom 4 (f03): X = mult(rd(X, Y), Y). 0.20/0.55 Axiom 5 (f04): rd(mult(X, Y), Y) = X. 0.20/0.55 Axiom 6 (f01): X = mult(Y, ld(Y, X)). 0.20/0.55 0.20/0.55 Goal 1 (goals): mult(mult(a, b), mult(a, c)) = mult(mult(a, a), mult(b, c)). 0.20/0.55 Proof: 0.20/0.55 mult(mult(a, b), mult(a, c)) 0.20/0.55 = { by axiom 2 (f02) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, c)), mult(mult(a, b), mult(a, c)))) 0.20/0.55 = { by axiom 1 (f06) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, b)), mult(mult(a, c), mult(a, c)))) 0.20/0.55 = { by axiom 1 (f06) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, b)), mult(mult(a, a), mult(c, c)))) 0.20/0.55 = { by axiom 3 (f05) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, a)), mult(mult(a, b), mult(c, c)))) 0.20/0.55 = { by axiom 6 (f01) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, a)), mult(mult(a, c), ld(mult(a, c), mult(mult(a, b), mult(c, c)))))) 0.20/0.55 = { by axiom 3 (f05) } 0.20/0.55 ld(mult(a, mult(a, c)), mult(mult(a, mult(a, c)), mult(mult(a, a), ld(mult(a, c), mult(mult(a, b), mult(c, c)))))) 0.20/0.55 = { by axiom 2 (f02) } 0.20/0.55 mult(mult(a, a), ld(mult(a, c), mult(mult(a, b), mult(c, c)))) 0.20/0.55 = { by axiom 6 (f01) } 0.20/0.55 mult(mult(a, a), ld(mult(a, c), mult(mult(rd(mult(a, c), c), ld(rd(mult(a, c), c), mult(a, b))), mult(c, c)))) 0.20/0.55 = { by axiom 1 (f06) } 0.20/0.55 mult(mult(a, a), ld(mult(a, c), mult(mult(rd(mult(a, c), c), c), mult(ld(rd(mult(a, c), c), mult(a, b)), c)))) 0.20/0.55 = { by axiom 4 (f03) } 0.20/0.55 mult(mult(a, a), ld(mult(a, c), mult(mult(a, c), mult(ld(rd(mult(a, c), c), mult(a, b)), c)))) 0.20/0.55 = { by axiom 2 (f02) } 0.20/0.55 mult(mult(a, a), mult(ld(rd(mult(a, c), c), mult(a, b)), c)) 0.20/0.55 = { by axiom 5 (f04) } 0.20/0.55 mult(mult(a, a), mult(ld(a, mult(a, b)), c)) 0.20/0.55 = { by axiom 2 (f02) } 0.20/0.55 mult(mult(a, a), mult(b, c)) 0.20/0.55 % SZS output end Proof 0.20/0.55 0.20/0.55 RESULT: Unsatisfiable (the axioms are contradictory). 0.20/0.55 EOF