heqs

from The Free On-line Dictionary of Computing (8 July 2008)

HEQS

   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).