Correspondence is a framework for interactively visualizing correspondences between items in related blocks.
This page contains an example of a translation where each block consists of multiple lines. It is an example of translating code in the Ruby programming language into English.
Check the "Interleaved" checkbox, to see the blocks interleaved with each other so that corresponding lines within the two blocks are immediately adjacent.
And uncheck to go back to the original un-interleaved view.