User-Supplied Derivatives.

  If AUTO-constant JAC equals 0 then derivatives need not be specified in FUNC, BCND, ICND, and FOPT; see Section sec:JAC. If JAC=1 then derivatives must be given. This may be necessary for sensitive problems, and is recommended for computations in which AUTO generates an extended system. Examples of user-supplied derivatives can be found in demos dd2, int, plp, opt, and ops.