resource foo()
  var x := 0
  op p1() {send}
  send p1()      # fork p1
  proc p1()
      x +:= 3
  end
  var a[10]: int
  fa i := 1 to 10 -> a[i] := i af
  op p2() {send} 
  send p2()      # fork p2
  proc p2()
      x +:= 4
  end
end
