text:       SUBROUTINE DINTF (ANSWER, WORK, IOPT)
  c Copyright (c) 1996 California Institute of Technology, Pasadena, CA.
  c ALL RIGHTS RESERVED.
  c Based on Government Sponsored Research NAS7-03001.
  C>> 1996-04-26 DINTF  Krogh  Added ANSWER=0, for getting prototypes.
  C>> 1994-10-20 DINTF  Krogh  Changes to use M77CON
  C>> 1990-01-23 DINTF  CLL Added type stmts. Avoids msgs from compilers.
  C>> 1988-06-07 DINTF  Snyder  Replaced " by '.
  C>> 1987-08-14 DINTF  Snyder  Initial code.
  c--D replaces "?": ?INTF, ?INT
  C
  C     Dummy DINTF subprogram that prints
  C     'You have neglected either to write the DINTF subprogram'
  C     'or to select reverse communication before invoking DINT.'
  C     and then STOPs.
  C
        double precision ANSWER, WORK(*)
        integer IOPT(*)
        ANSWER = 0.D0
        PRINT *,'You have neglected either to write the DINTF subprogram'
        PRINT *,'or to select reverse communication before invoking DINT*'
        STOP
        END
  