Zulip Chat Archive

Stream: Is there code for X?

Topic: Vector subspace of maximal dimension is top


Stepan Nesterov (Nov 10 2025 at 19:48):

Is the following theorem equivalent to a theorem in mathlib:

example {K : Type*} [Field K] (V : Type*) [AddCommGroup V] [Module K V] [Module.Finite K V]
  [Module.Free K V] (U : Submodule K V) (hUV : Module.rank K U = Module.rank K V) : U =  := by
  sorry

Aaron Liu (Nov 10 2025 at 19:53):

import Mathlib

example {K : Type*} [Field K] (V : Type*) [AddCommGroup V] [Module K V] [Module.Finite K V]
  [Module.Free K V] (U : Submodule K V) (hUV : Module.rank K U = Module.rank K V) : U =  := by
  apply Submodule.eq_of_le_of_finrank_eq le_top
  apply Module.finrank_eq_of_rank_eq
  rw [Module.finrank_eq_rank', hUV, rank_top]

Kenny Lau (Nov 10 2025 at 19:57):

https://loogle.lean-lang.org/ is an excellent tool to find lemmas. It contains instructions at the bottom.


Last updated: Dec 20 2025 at 21:32 UTC