/// <summary>
/// Performs a "minus" of set <c>b</c> from set <c>a</c>. This returns a set of all
/// the elements in set <c>a</c>, removing the elements that are also in set <c>b</c>.
/// The original sets are not modified during this operation. The result set is a <c>Clone()</c>
/// of set <c>a</c> containing the elements from the operation.
/// </summary>
/// <param name="a">A set of elements.</param>
/// <param name="b">A set of elements.</param>
/// <returns>A set containing <c>A - B</c> elements. <c>null</c> if <c>a</c> is <c>null</c>.</returns>
public static Set Minus(Set a, Set b)
{
if (a == null)
{
return(null);
}
else
{
return(a.Minus(b));
}
}
/// <summary>
/// Performs a "minus" of set <c>b</c> from set <c>a</c>. This returns a set of all
/// the elements in set <c>a</c>, removing the elements that are also in set <c>b</c>.
/// The original sets are not modified during this operation. The result set is a <c>Clone()</c>
/// of set <c>a</c> containing the elements from the operation.
/// </summary>
/// <param name="a">A set of elements.</param>
/// <param name="b">A set of elements.</param>
/// <returns>A set containing <c>A - B</c> elements. <c>null</c> if <c>a</c> is <c>null</c>.</returns>
public static Set Minus(Set a, Set b)
{
if(a == null)
return null;
else
return a.Minus(b);
}
