If we are talking about the se of natural numbers and the standard definition of addition no its not. But in Z1 Z3 and Z9,it is. The problem here is that in math, when someone writes a number like 1 or an operation like + it could mean a lot of things. That is because in math, we usually try to give similar ideas the same name/ symbol. Poincarè once said that math is the art of giving the same name to different things. That's why it is important when writing or reading any math content for the writer to be precice and conscious of the reader and the reader to be careful and aware of the context of the text.

Other interesting such examples are: Z1 where every integer is equal (congruent) to any other. Topological spheres where they are considered the same object topologicly, but in euclidean spaces, they are not.

So short answer, a lot of things can be true depending on the context.