The SNES solver for handling submesh

General
1

Hi ,If the BlockedNewtonsolver is called in dolfinx when dealing with discontinuous reference processing interfaces, then is there a similar interface that can be called for the SNES solver as well? This would be to meet the needs of solving problems that require the use of submesh

2

I have a proposed version within a PR:

3

Thank you， This is what I want. Also, I’m curious whether it, like the blocknewtosolver, requires entitymaps to characterize the interaction between two submesh

4

It will require that (through compiling F and J) before sending them in