Some of you were right, there is a sensible problem in names/scope I've not expected. But I've the answer to everything :)
What are libraries? There are application foundations. In other words, applications are built on top of libraries.
So let's make it as it should.
A libraries is a function which takes in arguments an other libraries or an end application.
Let loadlast be a function which bind to a symbol the eval of the last instruction of a file. And let use the arc evaluation syntax.
////////////// app.ext ////////////////////
(loadlast '"lib1.ext" 'MyLib1)
(loadlast '"lib2.ext" 'MyLib2)
(loadlast '"lib3.ext" 'MyLib3)
'(*put your application here*))
(MyLib1 '(MyLib2 '(Mylib3 MyApp))) ; This launches the whole
MyApp ; that makes MyApp a lib. MyApp is working with MyLib1, MyLib2 and MyLib3 and thus must be embed at least on top of a stack which contains them.
///////////// lib1.ext ////////////////////
arg1; it evaluates (MyLib2 '(Mylib3 MyApp)) which can now use lib1 via the dynamic scope system