4 ms·

Forall X – An Introduction to Formal Logic

58 points by anupj 4y ago

spinningslate 4y ago
Logic is my favourite branch of maths. It still boggles my brain to think that the fearsome complexity of computing today ultimately boils down to True, False and a handful of logical connectives (conjunction, disjunction, negation).
- jonnycomputer 4y ago
  Point taken (and agreed), but it doesn't really. A boolean logic isn't going to get you sequential circuits, for example. You need recursion for that.
  - cscurmudgeon 4y ago
    To complete, you need first-order logic. https://www.cs.nmsu.edu/historical-projects/Projects/FoLundecidability.pdf https://www.cs.nmsu.edu/historical-projects/Projects/FoLunde...
  - carapace 4y ago
    You can do recursion in Boolean logic. It leads to imaginary Boolean values. See "Laws of Form". https://en.wikipedia.org/wiki/Laws_of_Form https://en.wikipedia.org/wiki/Laws_of_Form
creata 4y ago
Why do there seem to be so many forks of this book, like: https://openlogicproject.org/2017/01/18/forall-x-calgary-remix/ https://openlogicproject.org/2017/01/18/forall-x-calgary-rem...
- CuriousCosmic 4y ago
  It's an open source textbook so professors will tweak it to suit the course they specifically want to teach. There may be parts of it that they aren't fans of or would prefer to be done a different way so they can make those changes they want and share the ebook with their class. Ideally more classes would be able to do stuff like this but given the fairly "fixed"/closed source nature of most textbooks, this isn't really an option for most professors or courses.
jonnycomputer 4y ago
I used this book to teach an introduction to logic class. The students certainly appreciated not having to pay >$100 for a text book that they wouldn't read.
- gyulai 4y ago
  The subject matter covered is so ancient & timeless that there are plenty of cheap "dover reprint" type books, and even books in the public domain. The spirit of open access / open source in relation to textbooks is commendable of course, but I don't think $100 is the benchmark here.
michaelmior 4y ago
I think the title might better off start with "forall x" as on the link instead of "Forallx"

58 points by anupj 4y ago

Logic is my favourite branch of maths. It still boggles my brain to think that the fearsome complexity of computing today ultimately boils down to True, False and a handful of logical connectives (conjunction, disjunction, negation).

jonnycomputer 4y ago
Point taken (and agreed), but it doesn't really. A boolean logic isn't going to get you sequential circuits, for example. You need recursion for that.
- cscurmudgeon 4y ago
  To complete, you need first-order logic. https://www.cs.nmsu.edu/historical-projects/Projects/FoLundecidability.pdf https://www.cs.nmsu.edu/historical-projects/Projects/FoLunde...
- carapace 4y ago
  You can do recursion in Boolean logic. It leads to imaginary Boolean values. See "Laws of Form". https://en.wikipedia.org/wiki/Laws_of_Form https://en.wikipedia.org/wiki/Laws_of_Form

creata 4y ago

Why do there seem to be so many forks of this book, like: https://openlogicproject.org/2017/01/18/forall-x-calgary-remix/ https://openlogicproject.org/2017/01/18/forall-x-calgary-rem...

CuriousCosmic 4y ago
It's an open source textbook so professors will tweak it to suit the course they specifically want to teach. There may be parts of it that they aren't fans of or would prefer to be done a different way so they can make those changes they want and share the ebook with their class. Ideally more classes would be able to do stuff like this but given the fairly "fixed"/closed source nature of most textbooks, this isn't really an option for most professors or courses.

jonnycomputer 4y ago

I used this book to teach an introduction to logic class. The students certainly appreciated not having to pay >$100 for a text book that they wouldn't read.

gyulai 4y ago
The subject matter covered is so ancient & timeless that there are plenty of cheap "dover reprint" type books, and even books in the public domain. The spirit of open access / open source in relation to textbooks is commendable of course, but I don't think $100 is the benchmark here.

michaelmior 4y ago

I think the title might better off start with "forall x" as on the link instead of "Forallx"