A cute programming puzzle: RoboZZle 10460: Programmed Snake. (Yes, it is related to logic.)

If statements A and B are false, and you derive a third statement C, can a set of statements containing A, B and C still be consistent?

@jo_1 As I hinted earlier, you're confusing basic notions here.

Consistency is different from truth.

@user21820 Is a valid sentence necessarily true, or is valid just synonymous with semantic consequence?

@user525966 What does "valid" mean? I don't think I have ever used that term when teaching you, nor do I know what it is supposed to mean.

@jo_1: By the way, I recommend you actually learn a deductive system for logic first before we even talk about the notion of consistency. If not you would be trying to bite off more than you can chew, and it will just be very confusing. We cannot study formal systems in a vacuum; we need to study it from within a meta-system, which itself is a formal system, so you still need to know how to use one before you can perform solid logical reasoning about logic...

I think consistent means an interpretation exists that satisfies two sentences (or a sentence against some set of sentences)

@user525966 That's not the definition of "consistent".

The term for what you wrote is "satisfiable".

@user21820 intrologic.stanford.edu/public/… (page 2)

@user525966 That's not standard mathematical logic.