0.02/0.10	% Problem    : theBenchmark.p : TPTP v0.0.0. Released v0.0.0.
0.02/0.11	% Command    : twee %s --tstp --casc --quiet --explain-encoding --conditional-encoding if --smaller --drop-non-horn
0.10/0.31	% Computer   : n029.cluster.edu
0.10/0.31	% Model      : x86_64 x86_64
0.10/0.31	% CPU        : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
0.10/0.31	% Memory     : 8042.1875MB
0.10/0.31	% OS         : Linux 3.10.0-693.el7.x86_64
0.10/0.31	% CPULimit   : 960
0.10/0.31	% WCLimit    : 120
0.10/0.31	% DateTime   : Thu Jul  2 06:50:15 EDT 2020
0.16/0.31	% CPUTime    : 
0.17/0.51	% SZS status Theorem
0.17/0.51	
0.17/0.51	% SZS output start Proof
0.17/0.51	Take the following subset of the input axioms:
0.17/0.53	  fof(axiom_5, axiom, ![X]: is_a_theorem(implies(possibly(X), necessarily(possibly(X)))) <=> axiom_5).
0.17/0.53	  fof(axiom_m10, axiom, axiom_m10 <=> ![X]: is_a_theorem(strict_implies(possibly(X), necessarily(possibly(X))))).
0.17/0.53	  fof(hilbert_op_equiv, axiom, op_equiv).
0.17/0.53	  fof(hilbert_op_implies_and, axiom, op_implies_and).
0.17/0.53	  fof(km5_axiom_5, axiom, axiom_5).
0.17/0.53	  fof(km5_necessitation, axiom, necessitation).
0.17/0.53	  fof(necessitation, axiom, necessitation <=> ![X]: (is_a_theorem(X) => is_a_theorem(necessarily(X)))).
0.17/0.53	  fof(op_strict_implies, axiom, op_strict_implies => ![X, Y]: necessarily(implies(X, Y))=strict_implies(X, Y)).
0.17/0.53	  fof(s1_0_m10_axiom_m10, conjecture, axiom_m10).
0.17/0.53	  fof(s1_0_op_equiv, axiom, op_equiv).
0.17/0.53	  fof(s1_0_op_implies, axiom, op_implies).
0.17/0.53	  fof(s1_0_op_strict_implies, axiom, op_strict_implies).
0.17/0.53	
0.17/0.53	Now clausify the problem and encode Horn clauses using encoding 3 of
0.17/0.53	http://www.cse.chalmers.se/~nicsma/papers/horn.pdf.
0.17/0.53	We repeatedly replace C & s=t => u=v by the two clauses:
0.17/0.53	  fresh(y, y, x1...xn) = u
0.17/0.53	  C => fresh(s, t, x1...xn) = v
0.17/0.53	where fresh is a fresh function symbol and x1..xn are the free
0.17/0.53	variables of u and v.
0.17/0.53	A predicate p(X) is encoded as p(X)=true (this is sound, because the
0.17/0.53	input problem has no model of domain size 1).
0.17/0.53	
0.17/0.53	The encoding turns the above axioms into the following unit equations and goals:
0.17/0.53	
0.17/0.53	Axiom 1 (axiom_5_1): fresh99(X, X, Y) = true.
0.17/0.53	Axiom 2 (axiom_m10): fresh91(X, X) = true.
0.17/0.53	Axiom 3 (necessitation_1): fresh34(X, X, Y) = is_a_theorem(necessarily(Y)).
0.17/0.53	Axiom 4 (necessitation_1): fresh33(X, X, Y) = true.
0.17/0.53	Axiom 5 (op_strict_implies): fresh23(X, X, Y, Z) = strict_implies(Y, Z).
0.17/0.53	Axiom 6 (hilbert_op_implies_and): op_implies_and = true.
0.17/0.53	Axiom 7 (hilbert_op_equiv): op_equiv = true.
0.17/0.53	Axiom 8 (necessitation_1): fresh34(necessitation, true, X) = fresh33(is_a_theorem(X), true, X).
0.17/0.53	Axiom 9 (axiom_m10_1): fresh90(axiom_m10, true, X) = is_a_theorem(strict_implies(possibly(X), necessarily(possibly(X)))).
0.17/0.53	Axiom 10 (axiom_m10): fresh91(is_a_theorem(strict_implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true) = axiom_m10.
0.17/0.53	Axiom 11 (axiom_5_1): fresh99(axiom_5, true, X) = is_a_theorem(implies(possibly(X), necessarily(possibly(X)))).
0.17/0.53	Axiom 12 (op_strict_implies): fresh23(op_strict_implies, true, X, Y) = necessarily(implies(X, Y)).
0.17/0.53	Axiom 13 (km5_necessitation): necessitation = true.
0.17/0.53	Axiom 14 (km5_axiom_5): axiom_5 = true.
0.17/0.53	Axiom 15 (s1_0_op_strict_implies): op_strict_implies = true.
0.17/0.53	Axiom 16 (s1_0_op_implies): op_implies = true.
0.17/0.53	Axiom 17 (s1_0_op_equiv): op_equiv = true.
0.17/0.53	
0.17/0.53	Lemma 18: op_implies_and = op_implies.
0.17/0.53	Proof:
0.17/0.53	  op_implies_and
0.17/0.53	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.53	  true
0.17/0.53	= { by axiom 16 (s1_0_op_implies) }
0.17/0.53	  op_implies
0.17/0.53	
0.17/0.53	Lemma 19: is_a_theorem(strict_implies(possibly(X), necessarily(possibly(X)))) = fresh90(axiom_m10, op_implies_and, X).
0.17/0.54	Proof:
0.17/0.54	  is_a_theorem(strict_implies(possibly(X), necessarily(possibly(X))))
0.17/0.54	= { by axiom 9 (axiom_m10_1) }
0.17/0.54	  fresh90(axiom_m10, true, X)
0.17/0.54	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh90(axiom_m10, op_implies_and, X)
0.17/0.56	
0.17/0.56	Goal 1 (s1_0_m10_axiom_m10): axiom_m10 = true.
0.17/0.56	Proof:
0.17/0.56	  axiom_m10
0.17/0.56	= { by axiom 10 (axiom_m10) }
0.17/0.56	  fresh91(is_a_theorem(strict_implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 5 (op_strict_implies) }
0.17/0.56	  fresh91(is_a_theorem(fresh23(op_implies_and, op_implies_and, possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(is_a_theorem(fresh23(true, op_implies_and, possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 15 (s1_0_op_strict_implies) }
0.17/0.56	  fresh91(is_a_theorem(fresh23(op_strict_implies, op_implies_and, possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(is_a_theorem(fresh23(op_strict_implies, true, possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 12 (op_strict_implies) }
0.17/0.56	  fresh91(is_a_theorem(necessarily(implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X))))), true)
0.17/0.56	= { by axiom 3 (necessitation_1) }
0.17/0.56	  fresh91(fresh34(op_implies, op_implies, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(fresh34(op_implies_and, op_implies, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(fresh34(true, op_implies, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 13 (km5_necessitation) }
0.17/0.56	  fresh91(fresh34(necessitation, op_implies, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(fresh34(necessitation, op_implies_and, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(fresh34(necessitation, true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 8 (necessitation_1) }
0.17/0.56	  fresh91(fresh33(is_a_theorem(implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 11 (axiom_5_1) }
0.17/0.56	  fresh91(fresh33(fresh99(axiom_5, true, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 14 (km5_axiom_5) }
0.17/0.56	  fresh91(fresh33(fresh99(true, true, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(fresh33(fresh99(op_implies_and, true, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(fresh33(fresh99(op_implies, true, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(fresh33(fresh99(op_implies, op_implies_and, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(fresh33(fresh99(op_implies, op_implies, sK9_axiom_m10_X), true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 1 (axiom_5_1) }
0.17/0.56	  fresh91(fresh33(true, true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 16 (s1_0_op_implies) }
0.17/0.56	  fresh91(fresh33(op_implies, true, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(fresh33(op_implies, op_implies_and, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(fresh33(op_implies, op_implies, implies(possibly(sK9_axiom_m10_X), necessarily(possibly(sK9_axiom_m10_X)))), true)
0.17/0.56	= { by axiom 4 (necessitation_1) }
0.17/0.56	  fresh91(true, true)
0.17/0.56	= { by axiom 16 (s1_0_op_implies) }
0.17/0.56	  fresh91(op_implies, true)
0.17/0.56	= { by axiom 6 (hilbert_op_implies_and) }
0.17/0.56	  fresh91(op_implies, op_implies_and)
0.17/0.56	= { by lemma 18 }
0.17/0.56	  fresh91(op_implies, op_implies)
0.17/0.56	= { by axiom 2 (axiom_m10) }
0.17/0.56	  true
0.17/0.56	% SZS output end Proof
0.17/0.56	
0.17/0.56	RESULT: Theorem (the conjecture is true).
0.17/0.56	EOF