Residual Neural Network: Concatenation or Element

Question

With the residual block in residual neural networks, is the addition at the end of the block true element addition or is it concatenation?

For example, would addition([1, 2], [3, 4]) produce [1, 2, 3, 4] or [4, 6] ?

Answer 1

It would result in [4, 6], and you can find out more in this paper