MARK                   Prepare to Release Heap Space                 pp 120

 Syntax:  Mark (PtrVar) ;

 Type:    Pointer

 Form:    Procedure

 Purpose: Mark a point in heap space where all data from the marked point
          and higher are to be released from allocation.

 Notes:   Use DISPOSE to release only the memory allocated to the variable.
          PtrVar is a pointer variable.


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 Usage:
       VAR
          PtrVar : ^Integer ;

       BEGIN
          Mark (PtrVar)     ;
       END.