What do the subscripts mean in $N_{t,n,\sigma,L}$?

Question

A neural network can apparently be denoted as $N_{t,n,\sigma,L}$. What do these subscripts $t, n, \sigma$ and $L$ mean? Could you link me to a paper, article or webpage with an explanation for this?

Answer 1

Here is a paper with the mathematical definition of each term:

Let N_t,n,σ,L be all target functions that can be implemented using a neural network of depth t, size n, activation function σ, and when we restrict the input weights of each neuron to be |w|₁ + |b| ≤ L.