PR# 19274 Tuple-type-unfolded form with nested TUPLEs

This bug is related to bug#19273.

The following code is not correct:

  class BAR [G -> TUPLE [TUPLE [ANY]]] end 

   class FOO
   feature
      make
         local
            l_bar: BAR [STRING]
         do
            create l_bar
         end
   end 

Indeed, the Tuple-type-unfolded form of "BAR [STRING]" should be "BAR [TUPLE [STRING]]" (according to DJTT-3), but the actual generic parameter does not conform to the constraint "TUPLE [TUPLE [ANY]]". But surprisingly the compiler accepts the code and creates an object of type "BAR [TUPLE [TUPLE [STRING]]]". I did not understand where the second "TUPLE" is coming from (was DJTT-3 applied twice in a row?). 

--
Eric Bezault