feat(linear_algebra/basic): f x ∈ submodule.span R (f '' s) (#6453)
feat(linear_algebra/basic): f x ∈ submodule.span R (f '' s) (#6453)





Co-authored-by: Scott Morrison <63f04b4d96235eb042cc46d94f14d241d2a26722@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib