Test 3.LB+o-o+o-o

LISA 3.LB+o-o+o-o (*Paul says allowed*)
{
x = 0;
y = 0;
z = 0;
}
P0              | P1              | P2;
r[once] r1 x    | r[once] r3 y    | r[once] r4 z ;
w[once] y 1     | w[once] z 1     | w[once] x 1  ;
Observed
    2:r4=1; 1:r3=1; 0:r1=1;