Skip to content

[Merged by Bors] - chore(LinearAlgebra): golf of_mem_specialOrthogonalGroup_fin_two_iff using grind #30516

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

[Merged by Bors] - chore(LinearAlgebra): golf of_mem_specialOrthogonalGroup_fin_two_iff using grind #30516

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 1 addition & 9 deletions Mathlib/LinearAlgebra/UnitaryGroup.lean
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -284,15 +284,7 @@ lemma of_mem_specialOrthogonalGroup_fin_two_iff {a b c d : R} :
c * a + d * b = 0 ∧ c * c + d * d = 1) ∧ a * d - b * c = 1
· simp [Matrix.mem_specialOrthogonalGroup_iff, Matrix.mem_orthogonalGroup_iff,
← Matrix.ext_iff, Fin.forall_fin_succ, Matrix.vecHead, Matrix.vecTail]
refine ⟨?_, ?_⟩
· rintro ⟨⟨⟨h₀, h₁⟩, -, h₂⟩, h₃⟩
refine ⟨?_, ?_, ?_⟩
· linear_combination - a * h₂ + c * h₁ + d * h₃
· linear_combination - c * h₀ + a * h₁ - b * h₃
· linear_combination h₀
· rintro ⟨rfl, rfl, H⟩
ring_nf at H ⊢
tauto
grind

lemma mem_specialOrthogonalGroup_fin_two_iff {M : Matrix (Fin 2) (Fin 2) R} :
M ∈ Matrix.specialOrthogonalGroup (Fin 2) R ↔
Expand Down
Loading