In case you have difficulties with the presentation in horizontally juxtaposed columns, you can read this page <a href="http://lambdaway.free.fr/lambdawalks/?view=lambda_calculus" rel="nofollow">http://lambdaway.free.fr/lambdawalks/?view=lambda_calculus</a>. A simple question of choice. Personally I like the "horizontal" form allowing zooming + and - focusing on a column or displaying the whole, especially on a tablet or a smartphone.