node current (c : bool; x : int on c) returns ( y : int )
let
  y = merge c (true -> x) (false -> 0 fby y whenot c)
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node internal_current (c : bool; x : int on c) returns ( y : int on c)
var x_cur : int;
let
  x_cur = merge c (true -> x) (false -> 0 fby x_cur whenot c);
  y = x_cur when c
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node use_current (c : bool; x : int) returns (b : bool on c; y : int on c)
var x_cur, y2 :int;
let
  x_cur = current(c,x);
  y = x_cur when c;
  y2 = internal_current(c,x);
  b = y = y2;
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node prod() returns (y:int;b:bool)
var x,y':int;c,b':bool;
let
  x = 0 fby x + 1;
  c = (x % 10) = 0;
  (b',y') = use_current(c,x when c);
  y = current(c,y');
  b = merge c b' (true fby b whenot c);
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(* CHECK check *)
node check() returns (b:bool)
var y:int;
let
  (y,b) = prod()
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node main() returns (y:int;b:bool)
let
  (y,b) = prod()
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