Test Wo+Ro-rb-Ro+Wo-mb-Ro

LISA Wo+Ro-rb-Ro+Wo-mb-Ro
(* Allowed: rmb not transitive.  Also allowed by Power. *)
{
x = 0;
y = 0;
}
 P0            | P1           | P2           ;
 w[once] x 1   | r[once] r1 x | w[once] y 1  ;
               | f[rmb]       | f[mb]        ;
               | r[once] r2 y | r[once] r3 x ;
Observed
    2:r3=0; 1:r2=0; 1:r1=1;