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

  The SQRT function returns  a  real  value  that  represents  the
  square root of the specified parameter.

  Syntax:

     SQRT( x )

  The parameter 'x' can be of an integer, unsigned, or REAL  type.
  If the value of 'x' is less than zero, an error occurs.