LISA R+o-mb-o+o-wb-o (* Allow due to it being allowed PowerPC. *) { x = 0; y = 0; } P0 | P1 ; w[once] x 2 | w[once] y 1 ; f[mb] | f[wmb] ; r[once] r2 y | w[once] x 1 ; Observed x=2; 0:r2=0;