VMS Help PASCAL, Predeclared Routines, Arithmetic, UXOR  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The UXOR function returns an unsigned value of a binary  logical
  exclusive-OR  operation on the corresponding pair of bits of two
  specified parameters.

  Syntax:

     UXOR( u1,u2 )

  The parameters 'u1' and 'u2' must be unsigned.