VMS Help FORTRAN, Intrinsic Procedures, LLT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  LLT (character, character)

  A function that returns a value of true if the first character
  string is less than the second character string.  The arguments
  must be character expressions.  The ASCII collating sequence
  determines the relationship between the arguments.