4DL

# Preface FROM THE FUTURE! (2013) Where HQ9+ was a gag, 4DL began as a thought experiment. I was working at Charlie’s Espresso in Tempe at the time, and my shifts often had dead time that I used designing processor architectures and programming languages. I later learned, to my horror, that three- and four-dimensional instruction spaces are not actually uncommon (think: page-switching). I’ve preserved the 4DL definition below verbatim, in case people are curious. It contains an error, which I discovered early on but left in to see if anyone actually tried implementing the language. This became a habit.