feat(LinearAlgebra/AffineSpace/Independent): inf_affineSpan_eq_affineSpan_inter

[jsm28]

Add a lemma

lemma AffineIndependent.inf_affineSpan_eq_affineSpan_inter [Nontrivial k] {p : ι → P}
    (ha : AffineIndependent k p) (s₁ s₂ : Set ι) :
    affineSpan k (p '' s₁) ⊓ affineSpan k (p '' s₂) = affineSpan k (p '' (s₁ ∩ s₂)) := by

with a proof adapted from that of the existing weaker exists_mem_inter_of_exists_mem_inter_affineSpan, and change exists_mem_inter_of_exists_mem_inter_affineSpan to be proved using the new lemma.

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[github-actions]

PR summary 8aa3ccd118

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

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Declarations diff

+ AffineIndependent.inf_affineSpan_eq_affineSpan_inter

You can run this locally as follows

## summary with just the declaration names:
./scripts/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/declarations_diff.sh long <optional_commit>

The doc-module for script/declarations_diff.sh contains some details about this script.

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No changes to technical debt.

You can run this locally as

./scripts/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).