39348
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(* ========================================================================= *)
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(* CNF PROBLEMS *)
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39502
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(* Copyright (c) 2001 Joe Hurd, distributed under the BSD License *)
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39348
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(* ========================================================================= *)
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signature Problem =
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sig
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(* ------------------------------------------------------------------------- *)
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(* Problems. *)
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(* ------------------------------------------------------------------------- *)
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type problem =
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{axioms : Thm.clause list,
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conjecture : Thm.clause list}
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val size : problem -> {clauses : int,
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literals : int,
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symbols : int,
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typedSymbols : int}
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val freeVars : problem -> NameSet.set
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val toClauses : problem -> Thm.clause list
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val toFormula : problem -> Formula.formula
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val toGoal : problem -> Formula.formula
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val toString : problem -> string
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(* ------------------------------------------------------------------------- *)
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(* Categorizing problems. *)
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(* ------------------------------------------------------------------------- *)
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datatype propositional =
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Propositional
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| EffectivelyPropositional
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| NonPropositional
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datatype equality =
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NonEquality
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| Equality
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| PureEquality
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datatype horn =
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Trivial
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| Unit
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| DoubleHorn
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| Horn
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| NegativeHorn
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| NonHorn
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type category =
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{propositional : propositional,
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equality : equality,
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horn : horn}
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val categorize : problem -> category
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val categoryToString : category -> string
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end
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