[rspeer]

I don't see that implication at all.

Nobody is claiming that the definition of "differentiable programming" should be identical to the definition of "neural net". The claim is, if you want to assign a name to the thing that TensorFlow, PyTorch, and similar frameworks do, it's "differentiable programming".

If you want to make a non-differentiable neural net, knock yourself out. The research still exists and nobody is stopping you.

But while we're talking about terminology, I'd encourage you to stop referring to the units as "neurons". The false analogy to biology just confuses people.