nvironment where the names <var>V<sub>1</sub></var>, ... <var>V<sub>n</sub></var> are bound to fresh locations.  Hence, an aggregate-scope variable can be initialized by an initializer handler, updated by member handlers, and finally used to calculate the return value of the constructor.  If several aggregate data are nested, the handlers for interior data work on their own copy of the variable without fear of clobbering the value of the same for exterior data.  Handler code can be thus written in terms of 