Relay with 3 states simulink block

I need to model a 3-level relay for my control theory classes in simulink (or matlab, but would prefer simulink because I have all the simulations in simulink), however i cannot find a block for it neither can I make it using just relays and dead zones. Here's what I'm trying to simulate (I have a, b and B):

It is two normal relays and a dead zone between them. Serial connection of two relays of course does not cut it, as nonlinearities do not play by the superposition rule. Any help would be appreciated!

Answer 1

[Fangjun Jiang]

I was able to achieve it by this.