Loogle!

Result

Found 6 declarations mentioning LinearMap.trace and Module.Basis.

• Matrix.trace_toLin_eq 📋 Mathlib.LinearAlgebra.Trace
  {R : Type u} [CommSemiring R] {M : Type v} [AddCommMonoid M] [Module R M] {ι : Type w} [DecidableEq ι] [Fintype ι] (A : Matrix ι ι R) (b : Module.Basis ι R M) : (LinearMap.trace R M) ((Matrix.toLin b b) A) = A.trace
• LinearMap.trace_eq_matrix_trace 📋 Mathlib.LinearAlgebra.Trace
  (R : Type u) [CommSemiring R] {M : Type v} [AddCommMonoid M] [Module R M] {ι : Type w} [DecidableEq ι] [Fintype ι] (b : Module.Basis ι R M) (f : M →ₗ[R] M) : (LinearMap.trace R M) f = ((LinearMap.toMatrix b b) f).trace
• LinearMap.trace.eq_1 📋 Mathlib.LinearAlgebra.Trace
  (R : Type u) [CommSemiring R] (M : Type v) [AddCommMonoid M] [Module R M] : LinearMap.trace R M = if H : ∃ s, Nonempty (Module.Basis (↥s) R M) then LinearMap.traceAux R ⋯.some else 0
• LinearMap.trace_eq_matrix_trace_of_finset 📋 Mathlib.LinearAlgebra.Trace
  (R : Type u) [CommSemiring R] {M : Type v} [AddCommMonoid M] [Module R M] {s : Finset M} (b : Module.Basis (↥s) R M) (f : M →ₗ[R] M) : (LinearMap.trace R M) f = ((LinearMap.toMatrix b b) f).trace
• LinearMap.trace_eq_contract_of_basis 📋 Mathlib.LinearAlgebra.Trace
  {R : Type u_1} [CommRing R] {M : Type u_2} [AddCommGroup M] [Module R M] {ι : Type u_5} [Finite ι] (b : Module.Basis ι R M) : LinearMap.trace R M ∘ₗ dualTensorHom R M M = contractLeft R M
• LinearMap.trace_eq_contract_of_basis' 📋 Mathlib.LinearAlgebra.Trace
  {R : Type u_1} [CommRing R] {M : Type u_2} [AddCommGroup M] [Module R M] {ι : Type u_5} [Fintype ι] [DecidableEq ι] (b : Module.Basis ι R M) : LinearMap.trace R M = contractLeft R M ∘ₗ ↑(dualTensorHomEquivOfBasis b).symm

About

Loogle searches Lean and Mathlib definitions and theorems.

You can use Loogle from within the Lean4 VSCode language extension using (by default) Ctrl-K Ctrl-S. You can also try the #loogle command from LeanSearchClient, the CLI version, the Loogle VS Code extension, the lean.nvim integration or the Zulip bot.

Usage

Loogle finds definitions and lemmas in various ways:

1. By constant:
   🔍 Real.sin
   finds all lemmas whose statement somehow mentions the sine function.

2. By lemma name substring:
   🔍 "differ"
   finds all lemmas that have "differ" somewhere in their lemma name.

3. By subexpression:
   🔍 _ * (_ ^ _)
   finds all lemmas whose statements somewhere include a product where the second argument is raised to some power.

   The pattern can also be non-linear, as in
   🔍 Real.sqrt ?a * Real.sqrt ?a

   If the pattern has parameters, they are matched in any order. Both of these will find List.map:
   🔍 (?a -> ?b) -> List ?a -> List ?b
   🔍 List ?a -> (?a -> ?b) -> List ?b

4. By main conclusion:
   🔍 |- tsum _ = _ * tsum _
   finds all lemmas where the conclusion (the subexpression to the right of all → and ∀) has the given shape.

   As before, if the pattern has parameters, they are matched against the hypotheses of the lemma in any order; for example,
   🔍 |- _ < _ → tsum _ < tsum _
   will find tsum_lt_tsum even though the hypothesis f i < g i is not the last.

If you pass more than one such search filter, separated by commas Loogle will return lemmas which match all of them. The search
🔍 Real.sin, "two", tsum, _ * _, _ ^ _, |- _ < _ → _
would find all lemmas which mention the constants Real.sin and tsum, have "two" as a substring of the lemma name, include a product and a power somewhere in the type, and have a hypothesis of the form _ < _ (if there were any such lemmas). Metavariables (?a) are assigned independently in each filter.

The #lucky button will directly send you to the documentation of the first hit.

Source code

You can find the source code for this service at https://github.com/nomeata/loogle. The https://loogle.lean-lang.org/ service is provided by the Lean FRO.

This is Loogle revision 6ff4759 serving mathlib revision 602a93c