/// <summary>
/// Multiplication of the specified leftElement and rightElement.
/// </summary>
/// <param name="leftElement">Left element.</param>
/// <param name="rightElement">Right element.</param>
/// <returns>The multiplication of the leftElement and rightElement (leftElement * rightElement)</returns>
/// <exception cref="InvalidCastException">Thrown when the cast was not possible.</exception>
public DirectSum <T, TRing> Multiplication(
DirectSum <T, TRing> leftElement,
DirectSum <T, TRing> rightElement)
{
var tuple = leftElement.Multiply(rightElement) as DirectSum <T, TRing>;
if (tuple == null)
{
throw new InvalidCastException();
}
return(tuple);
}
