I think the subtler point is that the primitives have varying complexity, meaning that "get something by its key" is on the same level as the Mealy machine exam

I think the subtler point is that the primitives have varying complexity, meaning that "get something by its key" is on the same level as the Mealy machine example. It's messy to read and is also kind of a waste of valuable global namespace There's some nice magic in how quickly you can write mode as an expert, and part of the appeals of APLs are the power of some of the built-ins. There's likely other tools that would be more worthwhile in the `:;` spot than its current definition.