@kotk, I had a discussion a while back with the publisher of Gensler’s Logic textbooks about maintaining the existing LogiCola 2 codebase, and it unfortunately seems to have disappeared after his death. They were very interested in keeping LogiCola alive since dropping it would make them have to completely rewrite a lot of his more recent work. I did help them come up with a stop-gap method for running LogiCola on the then-new M1 MacBooks and Chromebooks, but I couldn’t commit to rewriting it while I was in school. I would email the publisher once you’re confident that you’ve hit feature parity, including a grading system for professors (my professor used it extensively), as they were very interested in an alternative/replacement system.

If you’d like, I can send you an email with the contact info of the person I talked to. Feel free to send me a Discord message (I’m my HN username with a single dot before it there).

Thank you for being so kind and thoughtful! The fact the software might fade away was a great motivation for myself. I'm in touch with the publisher and It's likely we'll keep working together. I'll reach out to you regardless as I'd love to learn from your insights :)

You may want to check how you normalize or distinguish the logical representations. On the propositional logic quiz I'm presented with choices like these:

  (R ^ L) v N    <- incorrect
  ((R ^ L) v N)  <- correct

  ((S -> G) v H) <- correct
  (S -> G) v H   <- incorrect

These pairs are the same, the extra parentheses don't change the meaning of the statements but only the ones with the extra parentheses are marked as correct.

Found some information on the actual notation for the book. The extra () fit the notation of the system from Gensler's book apparently. There doesn't appear to be a precedence order for the connectives, except that unary not (~) doesn't need the parens, ~P and P can both standalone.

The language he uses requires the extra parentheses whenever using any of v, ^, ->, or == (and, or, implication, equivalence/iff). This is probably a reasonable thing in context because it means the expressions can be cleanly combined as written and probably avoids confusion for students. They don't have to learn a precedence order.

So if a student ever arrives at these pair of statements:

  (P v Q)
  R

And they use and introduction they'll get:

  ((P v Q) ^ R)

No ambiguity, just combine the two as written and wrap in parens.

So I'll retract my previous feedback.

This is great! I'm so glad someone took the effort to do this. I discovered Logicola as part of ordering and reading his Formal Ethics text book. His books had a way of making modal logic feel accessible enough for me to learn. I also quite enjoyed Formal Ethics, which was a book devoted to deriving the Golden Rule from first principles, a set of four non-controversial axioms. I had fun working through it and creating my own cheat sheet LaTeX document showing the complete derivation, including the final representation of the "strict" version of the Golden Rule in modal logic notation. I actually put that on our wedding poster when my wife and I got married, and sent a photo of it to Gensler. He got a kick out of that.

I remember also asking him if it could be derived with constructive logic rather than by contradiction. He didn't have a fitch proof of that sort but thought it should be possible.

I'm taking one of the tests and the feedback seems strange: although it appears I got it right, because the selected answer turns green, many of the other answers turn red (which usually indicates a failure) and other unselected answers also turn green. It's confusing.

Ah, Gensler. He wrote a great little book on Godel's Theorem:

https://www.amazon.com/Godels-Theorem-Simplified-Harry-Gensl...

It seems to me that many of the questions confuse language and logic. Or, at least, it seems more about philosophical logic than mathematical logic.

I used that! The DOS version. In college at University of Cincinnati. I actually forget what class it was. Some maths I think.

This was in the late 90s / early 2000s so well past the DOS era but old DOS apps were still in use here and there (and would still run on Windows).

Who is owner of the logicola name? Is it trademarked and do you have permission from the publisher/family of the original author?

Also, on the front page there is a link to logicola.com, which is a typo, I think.

Finally, I'm using ff on windows with a screen reader and when I press the chapters button on the web page, absolutely nothing happens, so it is not clear how I'm supposed to test the website.

The button appears to be hover only, which bad. On top of that, it expands content down to show the chapters, but if you move over and then down (instead of down then over), you exit the hover area and it closes. There are no visual indications of the boundaries of the hover area.