Title: Conflicting name not visible in embedded scope
Goal: Rename variable `Z' in the body of the fun expression to `C'.
Parameters: [{file,"var6.erl"},{position,50},{varname,"C"}].
Documentation: There is an existing variable with name `C', but it is bound 
 after the fun expression, so it is not visible there, and there is no
 conflict in using the same name in the embedded scope.
