Matrix Keypad routine

[T.Jackson]

(b & c) are variables that will only be hard coded if assigned with a fixed value. In Discrete mathematics, if we were to say, a(x) means something - then this is effectively a predicate since the variable x can take on many different forms. On the other hand, if we say A = 100 and it's a "real number", it is said to be a proposition because there is obvious truth in it. Clearly 100 is a real number.

In you opinion, what should we all be using?

Short answer is, in my opinion - use whatever works best for you. Focus on your strengths and if it gets the job done, call it a day