// Repetition code syndrome measurement
include "stdgates.inc";

qubit[3] q;
qubit[2] a;
bit[3] c;
bit[2] syn;

def syndrome(qubit[3] d, qubit[2] a) -> bit[2] {
  bit[2] b;
  cx d[0], a[0];
  cx d[1], a[0];
  cx d[1], a[1];
  cx d[2], a[1];
  measure a -> b;
  return b;
}
reset q;
reset a;
x q[0]; // insert an error
barrier q;
syn = syndrome(q, a);
if(int[2](syn)==1) x q[0];
if(int[2](syn)==2) x q[2];
if(int[2](syn)==3) x q[1];
c = measure q;