private static TermFunction SubstituteFunction(TermFunction function, Substitution theta)
{
if (!function.HasVariables)
return function;
var body = new List<Term>();
for (int i = 0; i < function.Arity; i++)
body.Add(SubstituteTerm(function.GetTerm(i), theta));
return new TermFunction(function.FunctionName, body.ToArray());
}
private TermFunction RenameFunction(TermFunction function, Dictionary<TermVariable, TermVariable> renamings)
{
if (!function.HasVariables)
return function;
var body = new List<Term>();
for (int i = 0; i < function.Arity; i++)
body.Add(RenameTerm(function.GetTerm(i), renamings));
return new TermFunction(function.FunctionName, body.ToArray());
}
private bool Matches(TermFunction function)
{
if (function.FunctionName != Name || function.Arity != _arity)
return false;
for (int i = 0; i < function.Arity; i++)
{
var term = function.GetTerm(i) as TermFunction;
if (_functions.ContainsKey(i) && term == null)
return false;
if (term != null)
if (!_functions.ContainsKey(i) || !_functions[i].Matches(term))
return false;
}
return true;
}