 longword
                                <span style="color:navy"><b>READ</b></span> getgridvaluebitmask <span style="color:navy"><b>WRITE</b></span> setgridvaluebitmask;
        
        <span style="color:navy"><b>FUNCTION</b></span> gridvaluetag (const index: integer;
                                              const falsevalue: integer): integer;
        <span style="color:navy"><b>PROCEDURE</b></span> updatetagvalue (const bitset: integer);
        <span style="color:navy"><b>PROCEDURE</b></span> gr