Test IRIW+o-rmb-o+o-mb-o

LISA IRIW+o-rmb-o+o-mb-o
(* Allow, rmb is not transitive. *)
{
x = 0;
y = 0;
}
 P0           | P1           | P2          | P3          ; 
 r[once] r1 x | r[once] r3 y | w[once] x 1 | w[once] y 1 ;
 f[rmb]       | f[mb]        |             |             ;
 r[once] r2 y | r[once] r4 x |             |             ;
Observed
    1:r4=0; 1:r3=1; 0:r2=0; 0:r1=1;