sET Language. A very high level language based on sets, designed by Jack schwartz at the Courant Institute in the early 1970s. It was possibly the first use of {list comprehension} notation. Data types include sets (unordered collections), tuples (ordered collections) and maps (collections of ordered pairs). Expressions may include quantifiers (' for each' and ' exists' ). The first Ada translator was written in sETL. see also IsETL, Proset, sETL2. ["Programming With sets - An Introduction to sETL", Jacob T. schwartz et al, springer 1986].