A derivative of SETL with Ada-like syntax developed at the University of Essen in 1990. Formerly known as SETL/E. ["SETL/E, A Prototyping System Based on Sets", E.E. Doberkat et al, in Tagungsband TOOL90, W. Zorn ed, pp. 109-118, U Karlsruhe, Nov 1990]. ["ProSet - A Language for Prototyping with Sets", E.-E. Doberkat et al, in Proc Third Intl Workshop on Rapid System Prototyping, N. Kanopoulos ed, IEEE Comp Soc Press, June 1992, pp. 235-248].