ValidArgumentChecker

Checks zeroth-order symbolic logical arguments for validity via the command line.

This project was written for personal educational purposes at the direction of my professor Michelle Cheatham, mostly to dip my toes into some data structures applications. Feel free to spin up the Repl at the bottom of this page to run the code without having to download and compile it.

Instructions

Type a logical argument or expression at the prompt and press Enter. The argument will be evaluated for logical validity (i.e. tautology via a truth table) and the result will be printed to the console.

Syntax

a-Z - propositions

0 - contradiction

1 - tautology

{ } - brackets

( ) - parentheses

~ - not

& - and

| - or

> - if-then

= - if and only if

, - separator

/ - quotient (deductive transition)

Commands

help Prints help page.

show-table Prints an abbreviated truth table for the previous argument.

show-tree Prints the syntax tree for the previous argument.

quit Ends the program.

Notes

• Operator precedence is as shown above
• Operators of equal precedence are read from left to right.
  • e.g. (P > Q > R) = ((P > Q) > R)
• Spaces can be used freely to improve readability.

Example

Premise 1: Either it is cloudy outside, or it is not raining.

Premise 2: It is raining.

Conclusion: Therefore, it is cloudy outside.

Using , to separate our premises, { } to group them, and / to draw our conclusion, this argument can be written:

{C | ~R, R} / C

We can also use the = operator to validate the logical equivalence of two expressions:

(~P | Q) = (P > Q)

(P & ~P) = 0

Repl

A repl exists for this project for the sake of convenience. If you'd like to check it out, follow this link.