|expr||Value||Value returned by mem(expr)|
|_maxAvail||-1||Returns the size (in bytes) of the largest available block of contiguous free memory in the heap. Also forces all purgeable resources to be removed from memory, and may move relocatable memory blocks.|
|_freeBytes||-2||Returns the total number of free bytes in the heap. This memory may be spread over several (non-contiguous) free blocks. This number always greater than or equal to the number returned by mem(_maxAvail).|
|indexID + _numElem||10-19||The element number of the highest element in this array that has been assigned a string, plus 1. Equals zero if no element has a string assigned to it. This number is also affected by the |
index D and
index I statements.