1C CoRW+poonceonce+Once
 2
 3(*
 4 * Result: Never
 5 *
 6 * Test of read-write coherence, that is, whether or not a read from
 7 * a given variable and a later write to that same variable are ordered.
 8 *)
 9
10{}
11
12P0(int *x)
13{
14	int r0;
15
16	r0 = READ_ONCE(*x);
17	WRITE_ONCE(*x, 1);
18}
19
20P1(int *x)
21{
22	WRITE_ONCE(*x, 2);
23}
24
25exists (x=2 /\ 0:r0=2)