You're welcome.The Arduino IDE only recognizes libraries in the 1.5 format if they have a library.properties. A library.properties file is not required for libraries in the Arduino library format 1.0 (source files in the library root folder) when using the Arduino IDE, but the Arduino Web Editor requires all libraries to have a library.properties file.Recursive compilation of 1.5 format libraries is done only on the src folder. Withe 1.0 format libraries, compilation is only done for files in the root and utility folders.
Well, actually #include "sublib/sub.h" according to your diagram, but you got the idea.
Thanks, I will try this in the afternoon.