You call everything a layer that touches Bitcoin, even if remotely. Are Cashu payments over nostr now layer 4?

If you don't have a definition of what a "layer"is, everything is a layer. If you call "sidechains" like Liquid not layers of Bitcoin, why do you call Fedimint one? They have the exact same trust model. I call neither one a layer.

Here's a useful definition: a system is called a Bitcoin layer, if conflicts in that can be truetlessly resolved in the layer below, with layer 1 being Bitcoin.

Lightning and Statechains are layer 2s. There are no layer 3s yet.