Test MP+o-rmb-o+o-mb-o

LISA MP+o-rmb-o+o-mb-o
(* Allow, rmb orders only reads. *)
{
x = 0;
y = 0;
}
 P0           | P1            ;
 w[once] y 1  | r[once] r1 x  ;
 f[rmb]       | f[mb]         ;
 w[once] x 1  | r[once] r2 y  ;
Observed
    1:r2=0; 1:r1=1;