Question

Converting english sentence to premises in discrete mathematics

Answer 1

In the language of first-order logic, this could be formalized as follows (there are in fact many ways, I'll just show one of them):

Let h denote the unary predicate "... is human", let m denote the unary predicate "... is mortal", and let z denote "Zeus".

Then your assumptions are

∀x.h x→m x

(read: "for all things, their humanness implies their mortality"), and

¬ m z

(read: "Zeus' mortality is not given").

By modus tollens, these two statements imply the conclusion

¬ h z

(read: "Zeus' humanness is not given").

In short:

∀x.h x→m x¬ m z¬ h z