E. Derman. Constraint language for financial modelling. Uses an extension of the equation solver in IDEAL. "A Simple Equation Solver and Its Application to Financial Modeling", E. Derman et al, Soft Prac & Exp 14(12):1169-1181 (Dec 1984).
HEQS
Meaning of HEQS in English
FOLDOC computer English dictionary. Английский словарь по компьютерам FOLDOC. 2012