Tagged Questions
2
votes
1answer
87 views
Model theory for intuitionistic predicate logic: non-empty domain?
In classical logic we tend to make the assumption the domain of quantification is non-empty. This isn't (too) problematic because classical mathematicians assume a language/mind/proof independent ...
4
votes
4answers
132 views
Help proving $ \sim \sim (p \to q),\sim \sim p \vdash \sim \sim q $ with intuitionistic axioms
Rule
modus ponens: $ p, p \to q \vdash q $
Axioms
A1 $ p \to (q \to p) $
A2 $ (p \to (q \to r)) \to ((p \to q) \to (p \to r)) $
A3 $ (p \land q) \to p $
A4 $ (p \land q) \to q $
A5 $ p \to ...
1
vote
1answer
101 views
A question on intuitionistc propositional logic
Prove that:
Two finite rooted frames are isomorphic iff they validate the same formulas.
(This is an exercise in the book "Modal Logic" by A.Chagrov and M.Zakharyaschev)
