CHECK

 The CHECK attribute specifies error-checking options that are to
 be enabled during program execution.

 Syntax:

    CHECK [[( {identifier},...  )]]

 An identifier specifies an option to be enabled.   If  you  omit
 the list of options, all available positive options are enabled.

    ALL                 Enables all forms of checking.

    NONE                Suppresses all checking code.

    [NO]BOUNDS          Verifies that an index expression is within
                        the bounds of an array's index type and that
                        character-string sizes are compatible with
                        the operations being performed and that 
                        schema types are compatible.
                        
    [NO]CASE_SELECTORS  Verifies that the value of a case selector
                        is contained in the corresponding case
                        label list.

    [NO]DECLARATIONS    Verifies that schema definitions yield 
                        valid types and that uses of GOTO from
                        one block to an enclosing block are correct.

    [NO]OVERFLOW        Verifies that the result of an integer 
                        computation does not exceed the machine 
                        representation.

    [NO]POINTERS        Verifies that the value of a pointer 
                        variable is not NIL.

    [NO]SUBRANGE        Verifies that values assigned to variables
                        of subrange types are within the subrange;
                        verifies that a set expression is assignment
                        compatible with a set variable.


 See the "HP Pascal Language Reference Manual" for  the  complete
 description of using the CHECK attribute.