Inspired by Ken Iverson’s paper “Notation as a Tool of Thought”, this podcast explores various aspects of notation, in the context of the APL programming language. Richard is the media manager and an APL instructor at Dyalog Ltd, has taught APL at multiple schools, and created an online self-study course. Adám is an APL programmer at Dyalog Ltd, launched the “APL Orchard” chat room and the “APLcart” code phrase search, and is the co-author of the “APL Cultivations” book. Both regular presenters at various APL events, and recurring panellists on the “Array Cast” podcast.