If you're interested in getting a firm grasp of airtight proofs -- with a view toward Haskell (and Agda and Idris) mastery -- you might want to pick and choose your way through the web-based proof exercises here:
This is a course firmly in the American analytic philosophy tradition, so Logic here is Symbolic Logic. Bonus: the course keeps AI and Machine Learning applications in the backdrop.
It's unfortunate that it's some kind of well-kept secret.
Those who don't need it -- because they've obtained the knowledge elsewhere -- won't know about it. And those who do want that knowledge also won't know about it.
Did I mention the exercises are web-based? Yes, you get instantaneous feedback on whether you've got a correct proof or not.