Understanding MPL

[gk at fsfe.org]

Hi!

I am currently reading the MPL 1.1, and have some basic problems
understanding it.

--8<---------------------------------------
3.7. Larger Works.
You may create a Larger Work by combining Covered Code with other code not
governed
by the terms of this License and distribute the Larger Work as a single
product.
In such a case, You must make sure the requirements of this License are
fulfilled for
the Covered Code.
--8<---------------------------------------

What does "combine" mean? Especially when modifications are defined as

--8<---------------------------------------
1.9. "Modifications" means any addition to or deletion from the substance
or structure
of either the Original Code or any previous Modifications.
--8<---------------------------------------

(1) Does that mean, that as long as somebody does not use lines from a
file of the Covered Code, he may distribute his proprietary code, which
calls functions of the Covered Code, in a single executable?

(2) Only when he alters the Covered Code, or uses portions of it in some
other file, that code would be under the Terms of the MPL?

(3) That would be similar to the LGPL, right?

(4) What about deriving a - for example Java - class from a class under
    (a) MPL
    (b) LGPL
Would the derived class be allowed to have a proprietary license?

Thank you very much in advance.

Regards, gk