AlgebraicCurves.Foundations.Algebra.Proofs.LinearMap_sum_neg_one_pow_mul_finrank_eq_zero_of_exact.P2mLES.finrank_eq_range_add_ker
Source context 7 commands
Surrounding namespaces, section variables, and local commands at this declaration.
section ProofImplementation
namespace AlgebraicCurves.Foundations.Algebra.Proofs
namespace LinearMap_sum_neg_one_pow_mul_finrank_eq_zero_of_exact
open Module
universe u v
namespace P2mLES
variable {k : Type u} [DivisionRing k]Lean source · statement
theorem finrank_eq_range_add_ker {M N : Type v} [AddCommGroup M] [Module k M] [AddCommGroup N]
[Module k N]
[Module.Finite k M] (f : M →ₗ[k] N) :
finrank k M = finrank k (LinearMap.range f) + finrank k (LinearMap.ker f)