feat(ring_theory): (strict) monotonicity of `coe_submodule` (#8273)
feat(ring_theory): (strict) monotonicity of `coe_submodule` (#8273)




Co-authored-by: Eric Wieser <da64e90baec5d084ce3d8e05f3b022ae6d118ff5@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib