principle of universal coverage is used to judge infringement, which is different from novelty and creativity.
generally speaking, the determination of infringement only compares the sovereign item with the product involved. If the technical features of the product involved fall within the protection scope of the claim, it constitutes infringement (including the same and equivalent situations). Other people's products only contain technologies A, C, D, lack technical features B, and have no equivalent technical features, so there is no infringement.
only A1, c and d have the same infringement judgment.
what if a in the previous part is changed a little bit to A1, b, c and d? Fall into the patent of ABCD? ——— See if A1 and A are equal, and if they are equal, they will fall into the protection scope, otherwise they will not fall into it.
Let's talk about the novelty of patent application. According to the provisions of the Patent Law, novelty means that the invention or utility model does not belong to the existing technology, and no unit or individual has filed an application for the same invention or utility model with the patent administration department of the State Council before the application date, and it is recorded in the patent application documents published or announced after the application date.
this criterion doesn't seem to be very consistent with your question? Are you asking creativity?
Also, in the example you cited, Claim 4 cited one sovereignty and two subordination rights, and these two subordination rights also cited the same sovereignty. This situation should not exist.
It should be added that being able to apply for a patent doesn't mean that you won't infringe on the product produced with the patent you applied for. If the new patent contains all the technical features of the previous patent, it will still be infringed without the permission of the holder of the previous patent. This often happens in legal practice.
you still need to understand some basic concepts .........................................
There are still some questions to ask.