it.unibz.inf.ontop.substitution

Interface Substitution

All Known Implementing Classes:

SingletonSubstitution, SubstitutionImpl

public interface Substitution

A substitution is a function of variables to terms. Terms can be: - Variables - Constants - Composite terms (Function). Typical algebraic operations on substitution functions are composition and union. See the SubstitutionUtilities

Method Summary

Modifier and Type	Method and Description
boolean	composeFunctions(Function term1, Function term2) Composes two functional terms.
boolean	composeTerms(Term term1, Term term2) Creates a singleton substitution out of term1 and term2.
Term	get(Variable var)
Map<Variable,Term>	getMap() Map representation of this function.
boolean	isEmpty()

Method Detail

get

Term get(Variable var)

getMap

Map<Variable,Term> getMap()

Map representation of this function.

isEmpty

boolean isEmpty()

composeTerms

boolean composeTerms(Term term1,
                     Term term2)

Creates a singleton substitution out of term1 and term2. Then, composes the current substitution with the latter. (remind that composition is not commutative). Note that the unifier will be modified in this process. The operation is as follows {x/y, m/y} composed with (y,z) is equal to {x/z, m/z, y/z}

Parameters:

term1 -

term2 -

Returns:

true if the substitution exists (false if it does not)

composeFunctions

boolean composeFunctions(Function term1,
                         Function term2)

Composes two functional terms. Can be recursive. Side-effect method: might add to new entries to the substitution.