<> <> DIRECTORY MathExpr USING [EXPR], ViewerClasses USING [Viewer], Rope USING [ROPE]; ViewExpr: CEDAR DEFINITIONS ~ BEGIN <> <<>> ROPE: TYPE ~ Rope.ROPE; Viewer: TYPE ~ ViewerClasses.Viewer; EXPR: TYPE ~ MathExpr.EXPR; <> Create: PROC[expr: EXPR _ NIL, name: ROPE] RETURNS[Viewer]; <> << Viewer will contain math expression expr. If expr = NIL, then>> << Viewer will contain an empty "placeholder".>> <<>> GetContents: PROC[viewer: Viewer] RETURNS[ROPE]; <> << a format understood by the AlgebraStructures parser.>> <<>> SetContents: PROC[viewer: Viewer, expr: EXPR]; <> <> << to be expr.>> <<>> <<>> << >> END.