# General
 - Documentation
 - Tests
 - CLI Options
 - Branding

# Internals
 - Non-recursive treeify
 - Syntax errors are broken

# Features
 - Function application
 - variable definitons
 - function definitions
 - rational datatype
 - units
 - Dice
 - Derivatives

# Prompt
 - Replace multi-char tokens (pi)
 - Arrows to move cursor
 - Live syntax/output
 - Commands
 - Better error texts