The Floating-Point Underflow Detection routine enables or
    disables floating-point underflow detection for the calling
    routine activation. The previous setting is returned as a
    function value.

    This routine is available on OpenVMS Alpha and I64 systems in
    translated form and is applicable to translated VAX images only.

    Format

      LIB$FLT_UNDER  new-setting

  Additional Information (explode) :

• Returns
• Argument