I've been looking at the web articles, and following statement seems to be true:When there is an application source code which just uses some GPL library, but does not contain any part of the library within the codebase, the developer of the application still needs to publish the application in GPL (if he/she is to publish the source code).Reference, for example,  https://softwareengineering.stackexchange.com/questions/317284/licensing-on-githubGiven my assumption is true, here's my question:Which part of the GPL License (http://www.gnu.org/licenses/gpl-3.0.txt) claims and enforces the library users to do so?Here, I think the to-be-published source code is not translated or in anyway interacted with the GPL library per se (as it is merely a source code), so I'm wondering how the above restriction gets logically deduced from the License statements.
Which statement of GPL enforces publishing source codes that uses GPL?
gpl