/// If arg is another Functor2, then succeed (yield once) if this and arg have the
/// same name and all functor args unify, otherwise fail (don't yield).
/// If arg is a Variable, then call its unify to unify with this.
/// Otherwise fail (don't yield).
public IEnumerable <bool> unify(object arg)
{
arg = YP.getValue(arg);
if (arg is Functor2)
{
Functor2 argFunctor = (Functor2)arg;
if (_name.Equals(argFunctor._name))
{
foreach (bool l1 in YP.unify(_arg1, argFunctor._arg1))
{
foreach (bool l2 in YP.unify(_arg2, argFunctor._arg2))
{
yield return(false);
}
}
}
}
else if (arg is Variable)
{
foreach (bool l1 in ((Variable)arg).unify(this))
{
yield return(false);
}
}
}
/// <summary>
/// If arg is another Functor, then succeed (yield once) if this and arg have the
/// same name and all functor args unify, otherwise fail (don't yield).
/// If arg is a Variable, then call its unify to unify with this.
/// Otherwise fail (don't yield).
/// </summary>
/// <param name="arg"></param>
/// <returns></returns>
public IEnumerable <bool> unify(object arg)
{
arg = YP.getValue(arg);
if (arg is Functor)
{
Functor argFunctor = (Functor)arg;
if (_name.Equals(argFunctor._name))
{
return(YP.unifyArrays(_args, argFunctor._args));
}
else
{
return(YP.fail());
}
}
else if (arg is Variable)
{
return(((Variable)arg).unify(this));
}
else
{
return(YP.fail());
}
}