The closed source commercial software (CSCS), will just make system calls to GPL applications.

The user machine will run CSCS and it will call these GPL applications in the very same way a user could use the command line and call the very same applications. Even a log of such actions could be provided, and user could replicate these actions manually.

The point is, the CSCS is calling a GPL application to just generate output, but in a predetermined way and hard coded on it, so CSCS depends on GPL app to work.

GPL app is NOT a library. Is a regular command line application.

Can the CSCS remain closed source on this sole specific situation?

I would appreciate also excerpts confirming the answer, thanks!

PS.: I have read this http://programmers.stackexchange.com/questions/47032/can-i-use-gpl-software-in-a-commercial-application?rq=1, and it doesnt seem to answer my specific question.