/sys$common/syshlp/helplib.hlb FORTRAN, Error Messages, Compilation Errors, OPENOTPER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  SEVERITY:  F

  MESSAGE TEXT:  Operation not permissible on these data types

  EXPLANATION:  An invalid operation was specified, such as an
  .AND. of two real variables.