LParse - A tiny language to render predicate logic arguments

I created this language in a weekend instead of actually doing my homework. You known, to optimize a 30 minute task (writing latex docs) into a minute or less!

The language itself took 48 hours to create, so obviously it was well worth it!

How to use it

LParse transforms its input into a .tex file containing valid LaTeX. You can then turn this document into a PDF, web page, etc. using the many available LaTeX renderers.

Every document has the following structure:

[config]
author: <Your name>
title: <Your document's title>
date: <Any string you want to be shown as a date>
default_clause: <Default method name. If you don't specify, it's "Arg">

[<section name>]
1) <equation> | <additional info>
2) <equation> | <additional info>
n+1) <equation> | <additional info>
|= <equation>

[<another section name>]
1) <equation> | <additional info>
2) <equation> | <additional info>
n+1) <equation> | <additional info>
|= <equation>

Language

The following definitions are simple examples designed to teach how to write documents. You are encouraged to look at the Technical section if you're lost.

equation

Is a set of expressions that represent some predicate logic.

• @x (p(x)) -> @ translates to "For all" followed by whatever is inside parenthesis or square brackets
• &e [p(x) -> g(x)] -> & translates to "Exists" followed by whatever is inside
• @x (&y [g(x) ^ p(y)])
• y ^ x -> ^ translates to and
• y V x -> V or V translates to or
• z -> x V m -> -> translates to the arrow operator
• ~z V (x ^ y) -> ~ translates to a negation

section name

Can contain anything other than square brackets ([]). Will be shown in the final output suffixed by a ), followed by the corresponding arguments, conclusion, etc.

• 1-b -> 1-b)
• proof of concept -> proof of concept)

additional_info

Anything you want to be shown after the equation. Usually, it's the method used to derive the argument. Must be inside a paranthesis (())

[Modus ponens]
1) p(x) -> q(x) | Premise
2) p(x) | Premise
3) q(x) | (M.p 1, 2)

config

The config section has special syntax which associates names (keys) with values. All values accept any string of characters, including spaces, all brackets, unicode, etc.

Keep in mind quotes are left as-is.

[config]
title = Assignment 1 - P.L
author = Diego Augusto
date = November of 2023

Technical

• <section name>: a string containing most unicode characters, except for square brackets ([]) and newlines.
• <pred_name>: a string containing only: ASCII alphanumeric characters, undescore (_) and hyphen (-)
• <expression> (also known as <expr>):
  • Existencials (you can use either () or []):
    • @<pred_name> (expr)
    • &<pred_name> (expr)
  • Binary operations:
    • <expr> -> <expr>
    • <expr> V <expr>
    • <expr> ^ <expr>
  • Negation:
    • ~<expr>
  • Sub expression:
    • (<expr>)
  • Functional predicates
    • <pred_name>([<expr>, <expr2>, ...])