Library /sys$common/syshlp/basichelp.hlb Compile time errors, EXPTOOCOM  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  ERROR  -  The  program  contains  an  expression  or   statement   too
  complicated  to  compile.   This  message  can occur whenever BASIC is
  unable to allocate sufficient  registers.   Recode  as  required;  for
  example,  rewrite  the  statement  as  two  or  more  less complicated
  statements.