function BlockSubRangeLevel: Integer;
Returns the current subrange stack level used by block processing functions.
Returns: Int32
Remarks:
When the stack has zero size, the subrange level is -1. This routine can be usefull for debugging purposes. When block processing is initiated with a call to BlockInit, the value of BlockSubRangeLevel is set to be equal to the current value of SubRangeLevel. When the block processing finishes, the BlockSubRangeLevel will be set to -1.