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Diff — Basis (linear algebra)

Revision #3435 → #4002 · back to history

modifiedSteinitz exchange lemma55fb74bbd56d
FieldFrom #3435To #4002
mathlib.declModule.Basis.extendexists_of_linearIndepOn_of_finite_span
mathlib.match_kindinvocationexact
mathlib.moduleMathlib.LinearAlgebra.Basis.VectorSpaceMathlib.LinearAlgebra.LinearIndependent.Lemmas
noteThe Steinitz exchange lemma is not stated under that name; its usual consequences (extending an independent set to a basis, invariance of dimension) are present via Basis.extend and mk_eq_mk_of_basis.exists_of_linearIndepOn_of_finite_span is the Steinitz exchange lemma: any linearly independent set in the span of a finite set t can be extended within s ∪ t to a set of the same cardinality as t.
statuspartialformalized
modifiedBasis as minimal generating set7a50fb978059
FieldFrom #3435To #4002
noteNo direct 'basis iff minimal spanning set' characterisation found in Mathlib.No direct 'basis iff minimal spanning set' characterisation for modules found in Mathlib (the analogous statement exists for matroids, not linear algebra).
modifiedCardinality of Hamel basis of R over Qe8e255802bb9
FieldFrom #3435To #4002
mathlib.decl—Real.rank_rat_real
mathlib.match_kind—exact
mathlib.module—Mathlib.LinearAlgebra.Complex.FiniteDimensional
noteNo Mathlib statement identifying the cardinality of a ℚ-basis of ℝ with the continuum.Real.rank_rat_real states Module.rank ℚ ℝ = Cardinal.continuum, i.e. any ℚ-basis of ℝ has continuum cardinality.
statusnot_formalizedformalized
addedLinear combinationa90ffab76aca
addedZorn's lemma07739b2dc2b5
addedCoordinate vectorb4321c90b6f0