Dear Experts, I'm a sort of newbe so be patient with if I ask something too silly (I've googled around but I didn't find anything really usefull). At the moment I'm investigating on how the OCaML module system and the separate compilation works. Nothing original I took the priority queue example from the user manual and split it into three files (attached): one with the structure (A.ml) one with the signature (A.mli) and one with a silly main (main.ml). Following the instructions in the manual I have tried to compile each file without linking but the only that compiles with success is the file with the signature since it doesn't refer to any other file. When I compile the structure or the main I get this error: >ocamlc -c A.ml File "A.ml", line 17, characters 39-52: Error: Unbound module type CharPQueueAbs I have tried to put #use or #load in the A.ml and main.ml file but the only result is to get a syntax error (e.g., with #use "A.mli" at the beggining of A.ml) >ocamlc -c A.ml File "A.ml", line 1, characters 0-1: Error: Syntax error What am I doing wrong? Any help is appreciate, thanks. Walter --