Shared Row Assignment
? Consider required transitions: e,c -> a
? Could implement as: e->a, c->a; or e->c->a; or c->e->a; or any of the above going through an intermediate state (or states).
? To avoid critical races, must ensure that {a,c,e} are placed in adjacent squares on the assignment map. Similar for other constraints. Must satisfy:
{a,c,e}, {b,d}, {a,b}, {c,d,f}, {b,c,f}, {a,d,e}, {a,c,d}, {e,f}