1 R = ID
   2 G = True
   3 { x = 0 }
   4 < x := x + 1 > || < x := x + 2 >
   5 { x = 3 }
   6 
   7 
   8 
   9 R = x(0, 2) x(1,3)
  10 G = x(0, 1), x(2, 3)
  11 { x = 0 \/ x = 2 }
  12 x := x + 1
  13 { x = 1 \/ x = 3 }
  14 
  15 R = x(0, 1) x(2,3)
  16 G = x(0, 2), x(1, 3)
  17 { x = 0 \/ x = 1 }
  18 x := x + 2
  19 { x = 2 \/ x = 3 }
  20 
  21 
  22 
  23 ===========================================
  24 
  25 
  26 c := false
  27 d := false
  28 ((while not c do skip); d := true) || ((while not d do skip); c := true)