a range from which to "subtract" subtrahend
a range to "subtracted" from minuend
The remaining pieces of minuend after removing subtrahend.
Both parameters are assumed to be ordered arrays.
This function does not assumes that overlap() has already been called with the same ranges and has returned true.
Returned array contains 0, 1, or 2 ranges which are the portion(s) of minuend that do not include subtrahend.
Caveat: This operator is not commutative.
Operator that subtracts one range from another.