It is fair to say that a complex description of permissions is harder to define and compare than a simple description. GPLv3 attempts to be international interp

It is fair to say that a complex description of permissions is harder to define and compare than a simple description. GPLv3 attempts to be international interpreted across different copyright laws and to a degree different languages, which makes the job even harder. But it also fair to point out that the basic permissions are fairly simple. Give the recipient source code of the whole work, put it under the same license, don't do something which a judge would deem as circumventing the authors intention of giving you those permissions. The above simplified version of copyleft would likely work fine, although I suspect every lawyer on the globe would hate it.