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# Class JavaAgent.resource.fopl.UnificationException

    java.lang.Object
       |
       +----java.lang.Throwable
               |
               +----java.lang.Exception
                       |
                       +----JavaAgent.resource.fopl.UnificationException

public class UnificationException
extends Exception

A UnificationException can occur in an attemt to extend a Substitution. When a Substitution is built up, usually during unification, new Variables that were not mentioned in the Substitution yet can be added to the Substitution. When two Variables are unified with each other they are part of the Substitution, but there is no Term in the Substitution they are being mapped to. Thus, when a Term is instantiated under a Substitution a new VarTerm with a new Variable is generated to which the old, unified Variables can be mapped. To avoid unifying this Variable again, a Substitution is blocked once such a new Variable has been generated. An attemt to extend a Substitution at this stage will cause a UnificationException.

See Also:
  Variable, Substitution

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UnificationException(String, Substitution)
  This constructor takes a String which should be a short message indicating why this exception was thrown and the Substitution from which it was thrown.

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getSubstitution()
  This function returns the Substitution in which the Exception occured.

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UnificationException

     public UnificationException(String str,
                                 Substitution subst)

  This constructor takes a String which should be a short message indicating why this exception was thrown and the Substitution from which it was thrown.

##

getSubstitution

     public Substitution getSubstitution()

  This function returns the Substitution in which the Exception occured.

  Returns:
    the Substitution in which the Exception occured

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