INTERFACE Spreadsheet; IMPORT Money; TYPE Grid: REF ARRAY OF ARRAY OF Money.T; T = OBJECT grid: Grid; name: TEXT; METHODS init (row, col: INTEGER): T; getCell (row, col: INTEGER): Money.T; putCell (row, col: INTEGER; value: Money.T); END; PROCEDURE Read (filename: TEXT): T; PROCEDURE Save (filename: TEXT; sheet: T); END Spreadsheet.