For the life of me, this sentence makes no sense to me, please advise. In addition, it provides mechanism for the redefinition of previously existing concepts without affecting backwards compatibility, but defining two or more non-composable layers, the level of compliance with the specification and backwards compatibility can be achieved without compromising clarity. Focus decryption on what "but defining two or more non-composable layers" represents.
Um, context? Without it, this sentence makes no sense to me, either. I used to write a lot of technical manuals for a living and this is exactly the kind of sentence I scrupulously avoided!
If that's your only problem with this sentence, you're more tolerant than I am. My first rewrite, eliminating what look to me like actual grammatical errors and removing confusing negatives that don't need to be there, would be: In addition, it provides a mechanism for the redefinition of existing concepts while maintaining backwards compatibility. The definition of two or more non-composable layers maintains backwards compatibility and compliance with the specification without compromising clarity. But that doesn't actually answer your question. If this were about software(?) my first guess would be that it means that we have two separate pieces of software that don't have any interfaces that can talk gracefully to one another. But we want them to talk to one another. So we're going to write two interfaces, one for each of the pieces of software, and we're going to write those two interfaces so that _they_ - the interfaces - can talk to each other, and therefore when we glue it all together (Software A - Interface One - Interface Two - Software B) we'll effectively have Software A and Software B talking to each other. Interface One and Interface Two are "non-composable" because the part that talks to the existing software is going to be really ugly, really specific code. But the combination of Software A and Interface One, and the combination of Software B and Interface Two, _will_ be composable, because those two bolted-together combinations will be able to play nice with each other and follow some sort of existing standard for communication. This is a guess. Entirely a guess. It's a guess as to the meaning of the sentence and a guess as to the meaning of "composable" in this context. ChickenFreak Edited to add: To put it a slightly different way, if Joe talks Russian and Fred talks Mandarin, they can talk to each other if they both learn French. And if _everybody_ speaks French, then that's more efficient than Fred learning Russian and Joe learning Mandarin, because they can use their French again with other people.
