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[Merged by Bors] - feat(Mathlib/RingTheory/Ideal/QuotientOperations): First Isomorphism Theorem for algebras #11027
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Thanks 🎉
bors merge
…Theorem for algebras (#11027) We add the First Isomorphism Theorem for algebras. (only the surjective version was present in mathlib). We also adjust the docstring on top of the file. Co-authored-by: Antoine Chambert-Loir <antoine.chambert-loir@math.univ-paris-diderot.fr>
{A B : Type*} [CommRing A] [Algebra R A] [Semiring B] [Algebra R B] | ||
(f : A →ₐ[R] B) : | ||
(A ⧸ RingHom.ker f) ≃ₐ[R] f.range := |
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The linter should complain about the spacing indentation ...
fun ⟨_y, hy⟩ => | ||
let ⟨x, hx⟩ := hy | ||
⟨x, SetCoe.ext hx⟩ |
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fun ⟨_y, hy⟩ => | |
let ⟨x, hx⟩ := hy | |
⟨x, SetCoe.ext hx⟩ | |
RingHom.rangeRestrict_surjective f |
(untested)
|
||
theorem ker_rangeRestrict (f : A →ₐ[R] B) : | ||
RingHom.ker f.rangeRestrict = RingHom.ker f := | ||
Ideal.ext fun _ ↦ Subtype.ext_iff |
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Ideal.ext fun _ ↦ Subtype.ext_iff | |
rfl |
(untested)
Pull request successfully merged into master. Build succeeded: |
…Theorem for algebras (#11027) We add the First Isomorphism Theorem for algebras. (only the surjective version was present in mathlib). We also adjust the docstring on top of the file. Co-authored-by: Antoine Chambert-Loir <antoine.chambert-loir@math.univ-paris-diderot.fr>
…Theorem for algebras (#11027) We add the First Isomorphism Theorem for algebras. (only the surjective version was present in mathlib). We also adjust the docstring on top of the file. Co-authored-by: Antoine Chambert-Loir <antoine.chambert-loir@math.univ-paris-diderot.fr>
…Theorem for algebras (#11027) We add the First Isomorphism Theorem for algebras. (only the surjective version was present in mathlib). We also adjust the docstring on top of the file. Co-authored-by: Antoine Chambert-Loir <antoine.chambert-loir@math.univ-paris-diderot.fr>
…Theorem for algebras (#11027) We add the First Isomorphism Theorem for algebras. (only the surjective version was present in mathlib). We also adjust the docstring on top of the file. Co-authored-by: Antoine Chambert-Loir <antoine.chambert-loir@math.univ-paris-diderot.fr>
We add the First Isomorphism Theorem for algebras.
(only the surjective version was present in mathlib).
We also adjust the docstring on top of the file.