Yes that not generated warning...   
      
   If we have   
      
   f(a)==(#a<4=>[a];[[a.1,a.2],[a.2,a.3]])   
      
   a:=f("string")   
      
   f is compiled as String -> Any   
   (and not String -> List List Character)   
   even if the "a" above it seems to be "List List Character"   
      
   But this is the *only case* it is compiled as type->Any   
   (but I say some part of system recognized"a" as type Any)   
      
   For example if I write   
      
   f([1,2,3,4]) it is compiled as   
   List Positive Integer-> List List positive integer   
      
   f([x,2,3,4]) it is compiled as   
   List Polynomial Integer -> List List Polynomial Integer   
      
   Etc   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)