https://code.jsoftware.com/wiki/Essays/Incunabulum https://code.jsoftware.com/wiki/Essays/Incunabulum This is the arthurese micro APL implementation, which ins

https://code.jsoftware.com/wiki/Essays/Incunabulum https://code.jsoftware.com/wiki/Essays/Incunabulum This is the arthurese micro APL implementation, which inspired the J implementation - although IIRC the design for J was already well on its way at the time (and indeed, Iverson did not consider J a new language, but rather an improved APL dialect, so you could say the design goes back to 1956...) It likely also formed a draft for A/A+ which Arthur did at Morgan Stanley (open sourced at aplusdev.org, but unmaintained and rotting theese days) - which themselves led to the creation of K.