Compatibility with Older Versions.

  There are two changes compared to early versions of AUTO94: The user-supplied equations-files must contain the subroutine PVLS. For an example of use of PVLS see the demo pvl in Section 15.1. There is also a small change in the q.xxx data-file. If necessary, older AUTO94 files can be converted using the @94to97 command; see Section 3.5.