/* Day 6: Pgm 6.1               */
  /*                              */
  /* simple program without input */

   data a ;
    u = x*4 ;
    x = 3 ;
    y = x*4 ;
    n = _n_ ;
    output ;    * write obs in dataset a ;
    x = x + 1 ;
    n = _n_ ;
    output ;    * write another obs in dataset a ;
 run ;          * end of data step ;

   proc print data=a ;
    title 'may 29.ex1' ;
 run ;