+ $$\xymatrix{
+ \ar[r] &
+ *+[Fo]{q_0}
+ \ar[r]^{a\wedge\neg b}
+ \ar@(ul,ur)^{\neg a}
+ \ar[d]^{a\wedge b} &
+ *+[F]{q_2}
+ \ar@(ul,ur)^{\neg b}
+ \ar[d]^{b\vee\neg a}\\
+ & *+[Fo]{q_1} \ar@(dl,ul)^{true}
+ & *+[F]{q_3} \ar@(dr,ur)_{true}
+ }$$
+ Which leads to the following product TS:
+ $$\xymatrix{
+ \ar[dr] & s_0 & s_1 & s_2 & s_3\\
+ q_0 & *+[Fo]{}\ar[r]\ar[ddrrr] & *+[Fo]{}\ar[dr]\\
+ q_1 & *+[Fo]{}\ar[r]\ar@/_/[rrr] & *+[Fo]{}\ar[r] & *+[Fo]{}\ar@(u,r)\ar[r] & *+[Fo]{}\ar@/^/[lll]\\
+ q_2 & *+[F]{}\ar@/_/[rrr]\ar[dr] & & & *+[F]{}\ar@/^/[lll]\\
+ q_3 & *+[F]{}\ar@/_/[rrr]\ar[r] & *+[F]{}\ar[r] & *+[F]{}\ar@(u,r)\ar[r] & *+[F]{}\ar@/^/[lll]
+ }$$
+ Thus forexample the path: $(s_0s_3)^{\omega}$ is a counterexample.
+