<> <> <> DIRECTORY MathExpr, AlgebraClasses, Rope; Environment: CEDAR DEFINITIONS ~ BEGIN <> ROPE: TYPE ~ Rope.ROPE; EXPR: TYPE = MathExpr.EXPR; <> ResetEnvironment: PROC[]; <> InstallVariable: PROC[var: ATOM, value: EXPR]; <> LookupVariable: PROC[var: ATOM] RETURNS[value: EXPR]; <> << SIGNALS notFound if no association exists>> <<>> RemoveVariable: PROC[var: ATOM]; <> <> notFound: ERROR; END.