of a value of type
    <em>t</em>.<p>

      Every object and variable has a specified <em>extent</em> during
      which it can be operated upon.  The extents of denotations are
      unbounded; the extents of constants and variables are determined
      by their declarations.<p>

      Values of type "INTEGER" have the usual meanings.  The range of
      integer values is determined by the particular implementation of
      Obr.<p>

      Values of type "BOOLEAN" represent truth values.  Only two
      Bo