Consider a vocabulary with only four propositions, $A$, $B$, $C$, and $D$. How many models are there for the following sentences? $B\lor C$. $\lnot A\lor \lnot B \lor \lnot C \lor \lnot D$. $(A{:;{\Rightarrow}:;}B) \land A \land \lnot B \land C \land D$.