* Write benchmarks
* Optimize `#closure`, `#complement`
* Visualization in console and in IRuby (how to scale into 80-symbol or 1200px screen); SVG; TeX formatters
* Remove old git history related to mTOR project
* What about working with simgle intervals (their, length, relations etc)?
* (?) Make it possible to use intervals with non-numeric objects to be possible to use math expressions as interval boundaries
* May be we should check that boundary is an actual number, not a NaN