I've spent some time writing a tutorial on how to write logic and natural deductions using groff and eqn. I've also written a handful of pic and eqn macros for natural deduction.
https://github.com/siglun/logic-and-groff/blob/main/logic-with-groff.pdf Any comments are welcome. I've also found some problems when it comes to characters used in logic, and I do need help on how to implement those. They are U+22A2 ⊢ syntactic consequence AKA turnstile U+22A8 ⊨ semantic consequence AKA double turnstile Any pointers as to how to add odd niche characters to what is used by eqn? Yours Sigfrid -- Sigfrid Lundberg, Ph.D., System developer Lund, Sweden https://sigfrid-lundberg.se/ <http://sigfrid-lundberg.se/>
