[plt-scheme] Implementing constructors for environment interface

It seems to me that you are asking for solutions to problems in EOPL.
I would suggest posting questions on a solution *you* propose.

Matthias, to my shock :-), has provided you with some actual code. I
may be wrong, but I suspect that the code he has provided is not
really comprehensible to you. It is all pinned on the notion that data
are functions and functions are data. You may want to ask questions
about his code. Understanding the sections of EOPL you are working
through is important.

-- 

Cheers,

Marco