Exit procedure

  DECLARATION:  Exit

      PURPOSE:  Exits immediately from the current block

         UNIT:  System

      REMARKS:  When Exit is executed in a procedure or a function,
                it causes the procedure or function to return.  When Exit
                is called as a statement in part of a program, it causes the
                program to terminate.

      EXAMPLE:  Procedure Exercise;
                Begin
                   Repeat
                      If Keypressed Then Exit
                      Writeln('..');
                   Until FALSE;
                End;

                Begin
                   Exercise;
                End.