/// <summary>
/// Adds the specified fact.
/// </summary>
/// <param name="fact">The fact.</param>
/// <returns></returns>
public Index add(IFact fact)
{
IFact[] facts1 = new IFact[this._facts.Length + 1];
Array.Copy(this._facts, 0, facts1, 0, this._facts.Length);
facts1[this._facts.Length] = fact;
return(new Index(facts1, _hash + fact.GetHashCode()));
}
/// <summary>
/// Adds the specified fact.
/// </summary>
/// <param name="fact">The fact.</param>
/// <returns></returns>
public Index add(IFact fact)
{
IFact[] facts1 = new IFact[this._facts.Length + 1];
Array.Copy(this._facts, 0, facts1, 0, this._facts.Length);
facts1[this._facts.Length] = fact;
return new Index(facts1, _hash + fact.GetHashCode());
}