Writing a library

Hi !

I'm new to Eiffel and I need to write a library.
I tried using Eiffelstudio by making a new project "A_TEST_LIB" and
making a
class "A_TEST" with a feature "print_hello_world".
Then I made a second project "TEST_PROJECT" and wanted to do this:
test_object : A_TEST
test_object.print_hello_world

But code inside "TEST_PROJECT" can't see the class "A_TEST".
Can anyone tell me how to do this? That is: can anyone tell my how
to write a library for eiffel?

I also have another problem:
IDE on Mac is very unstable  so I would like to use the commandline.
But if I try to run "ec" I get this error:

/usr/local/share/eiffel6.1/ec/eifinit/general.cfg does not exist.
Execution impossible.


Thank you for your help!

Gloria