
package uk.ac.man.cs.lethe.internal.fol.unification

import uk.ac.man.cs.lethe.internal.fol.datatypes._

object TautologyChecker { 
  // Checks whether the clause is a tautology
  def tautology(clause: Clause): Boolean = { 
    clause.literals.exists{ l1 =>
      clause.literals.exists{ l2 =>
        l1!=l2 && 
	l1.positive!=l2.positive &&
	l1.predicate == l2.predicate
//	Unifier.unifies(l1.predicate, l2.predicate)
      }
    }
  }
}
