@begin: scope:[]  from
  [0] (byte) col1#0 ← (byte) 0
  [1] (byte) col2#0 ← (byte) 8
  to:@1
@1: scope:[]  from @begin
  [2] phi()
  [3] call main 
  to:@end
@end: scope:[]  from @1
  [4] phi()
main: scope:[main]  from @1
  [5] *((const void()**) KERNEL_IRQ#0) ← &interrupt(KERNEL_MIN)(void()) irq()
  to:main::@return
main::@return: scope:[main]  from main
  [6] return 
  to:@return
irq: scope:[irq]  from
  [7] *((const byte*) SCREEN#0+(byte) $28) ← (byte) col1#0
  [8] (byte) col1#1 ← ++ (byte) col1#0
  [9] *((const byte*) SCREEN#0+(byte) $29) ← (byte) col2#0
  [10] (byte) col2#1 ← ++ (byte) col2#0
  to:irq::@return
irq::@return: scope:[irq]  from irq
  [11] return 
  to:@return
