format = 5;       ! number of significant figures for output
 begin            ! start of BEGIN...END block
  out calc.dat ! activation of output procedure with calc.dat  name 
 end              ! end of block
end               ! end of main procedure
output calc.dat ! procedure for output of results to calc.dat file 
! generation of first string with variable names 
 if first then        ! FIRST - built-in key (takes value 0 or 1)
  first = 0;
   write1 ' n     void      xst  ';
 endif; ! end of block
! block for recording after 20 s values of elements arrays void and xst 
 if (tau > 20.) then;
  do i=1,20; ! cycle over all array elements
   write1 i,void(i),xst(i); ! writing of string to calc.dat  file 
enddo; ! end of cycle
  stop; ! stop of output procedure
 endif; ! end of block 
end ! end of output procedure