del  t v

    Delete the first instance of value v in table t
    The remaining entries are shifted left one index to avoid holes.
    Note that v is the value of the item to be deleted, not the index into the table.
    (To remove an item at a particular index, use deli instead)
    del returns the deleted item, or returns no value when nothing was deleted.

        A={1,10,2,11,3,12}
        FOR ITEM IN ALL(A) DO
            IF (ITEM < 10) THEN DEL(A, ITEM) END
        END
        FOREACH(A, PRINT) -- 10,11,12
        PRINT(A[3])       -- 12

deli t [i]

    Like del(), but remove the item from table t at index i.
    When i is not given, the last element of the table is removed and returned.