/ARITHMETIC={NATIVE,STANDARD}

  Specifies whether native arithmetic or standard arithmetic is used to
  evaluate arithmetic operations and statements.

  NATIVE              Selects native arithmetic.  Arithmetic operations
                      will produce results that are reasonably compatible
                      with releases of HP COBOL for OpenVMS Alpha prior
                      to V2.7 and also with HP COBOL for OpenVMS VAX.

  STANDARD            Selects standard arithmetic.  Most common arithmetic
                      operations will produce results that are predictable,
                      reasonable, and portable.  In this context, portable
                      means that the results will be identical from
                      implementation to implementation.  Choosing the STANDARD
                      option forces /MATH_INTERMEDIATE=CIT4.

  The default is /ARITHMETIC=NATIVE.