Skip to content
This repository has been archived by the owner on Jul 24, 2024. It is now read-only.

[Merged by Bors] - feat(algebra/field, ring_theory/ideal/basic): an ideal is maximal iff the quotient is a field #3986

Closed
wants to merge 10 commits into from

Conversation

AlexandruBosinta
Copy link
Collaborator

@AlexandruBosinta AlexandruBosinta commented Aug 30, 2020

One half of the theorem was already proven (the implication maximal
ideal implies that the quotient is a field), but the other half was not,
mainly because it was missing a necessary predicate.
I added the predicate is_field that can be used to tell Lean that the
usual ring structure on the quotient extends to a field. The predicate
along with proofs to move between is_field and field were provided by
Kevin Buzzard. I also added a lemma that the inverse is unique in
is_field.
At the end I also added the iff statement of the theorem.


an ideal is maximal iff the quotient is a field

One half of the theorem was already proven (the implication maximal
ideal implies that the quotient is a field), but the other half was not,
mainly because it was missing a necessary predicate.
I added the predicate is_field that can be used to tell Lean that the
usual ring structure on the quotient extends to a field. The predicate
along with proofs to move between is_field and field were provided by
Kevin Buzzard. I also added a lemma that the inverse is unique in
is_field.
At the end I also added the iff statement of the theorem.
@AlexandruBosinta AlexandruBosinta added the awaiting-review The author would like community review of the PR label Aug 30, 2020
@bryangingechen bryangingechen changed the title feat(algebra/field, ring_theory/ideal/basic): proof of the theorem that feat(algebra/field, ring_theory/ideal/basic): an ideal is maximal iff the quotient is a field Aug 30, 2020
predicate was given under square brackets

Seems like there is a problem when giving as an argument under square
brackets a predicate. I did not get this error on my device and I did
try leanproject build. The issue has been fixed along with a few other
minor changes to the features of my previous commit.
@Vierkantor Vierkantor self-requested a review August 31, 2020 11:14
Copy link
Collaborator

@Vierkantor Vierkantor left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks 🎉

I have a few formatting suggestions, but otherwise it looks good to me.

src/algebra/field.lean Outdated Show resolved Hide resolved
src/algebra/field.lean Outdated Show resolved Hide resolved
src/algebra/field.lean Outdated Show resolved Hide resolved
src/algebra/field.lean Outdated Show resolved Hide resolved
src/ring_theory/ideal/basic.lean Outdated Show resolved Hide resolved
src/ring_theory/ideal/basic.lean Outdated Show resolved Hide resolved
@Vierkantor Vierkantor added awaiting-author A reviewer has asked the author a question or requested changes and removed awaiting-review The author would like community review of the PR labels Aug 31, 2020
AlexandruBosinta and others added 7 commits August 31, 2020 15:55
Co-authored-by: Vierkantor <Vierkantor@users.noreply.github.com>
Co-authored-by: Vierkantor <Vierkantor@users.noreply.github.com>
Co-authored-by: Vierkantor <Vierkantor@users.noreply.github.com>
Co-authored-by: Vierkantor <Vierkantor@users.noreply.github.com>
Co-authored-by: Vierkantor <Vierkantor@users.noreply.github.com>
@AlexandruBosinta AlexandruBosinta added awaiting-review The author would like community review of the PR and removed awaiting-author A reviewer has asked the author a question or requested changes labels Aug 31, 2020
Copy link
Collaborator

@Vierkantor Vierkantor left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks for the fix!

bors r+

@github-actions github-actions bot added ready-to-merge All that is left is for bors to build and merge this PR. (Remember you need to say `bors r+`.) and removed awaiting-review The author would like community review of the PR labels Aug 31, 2020
bors bot pushed a commit that referenced this pull request Aug 31, 2020
… the quotient is a field (#3986)

One half of the theorem was already proven (the implication maximal
ideal implies that the quotient is a field), but the other half was not,
mainly because it was missing a necessary predicate.
I added the predicate is_field that can be used to tell Lean that the
usual ring structure on the quotient extends to a field. The predicate
along with proofs to move between is_field and field were provided by
Kevin Buzzard. I also added a lemma that the inverse is unique in
is_field.
At the end I also added the iff statement of the theorem.




Co-authored-by: AlexandruBosinta <32337238+AlexandruBosinta@users.noreply.github.com>
@bors
Copy link

bors bot commented Aug 31, 2020

Pull request successfully merged into master.

Build succeeded:

@bors bors bot changed the title feat(algebra/field, ring_theory/ideal/basic): an ideal is maximal iff the quotient is a field [Merged by Bors] - feat(algebra/field, ring_theory/ideal/basic): an ideal is maximal iff the quotient is a field Aug 31, 2020
@bors bors bot closed this Aug 31, 2020
@bors bors bot deleted the AlexandruBosinta branch August 31, 2020 17:04
robertylewis pushed a commit that referenced this pull request Aug 31, 2020
… the quotient is a field (#3986)

One half of the theorem was already proven (the implication maximal
ideal implies that the quotient is a field), but the other half was not,
mainly because it was missing a necessary predicate.
I added the predicate is_field that can be used to tell Lean that the
usual ring structure on the quotient extends to a field. The predicate
along with proofs to move between is_field and field were provided by
Kevin Buzzard. I also added a lemma that the inverse is unique in
is_field.
At the end I also added the iff statement of the theorem.




Co-authored-by: AlexandruBosinta <32337238+AlexandruBosinta@users.noreply.github.com>
PatrickMassot pushed a commit that referenced this pull request Sep 8, 2020
… the quotient is a field (#3986)

One half of the theorem was already proven (the implication maximal
ideal implies that the quotient is a field), but the other half was not,
mainly because it was missing a necessary predicate.
I added the predicate is_field that can be used to tell Lean that the
usual ring structure on the quotient extends to a field. The predicate
along with proofs to move between is_field and field were provided by
Kevin Buzzard. I also added a lemma that the inverse is unique in
is_field.
At the end I also added the iff statement of the theorem.




Co-authored-by: AlexandruBosinta <32337238+AlexandruBosinta@users.noreply.github.com>
Sign up for free to subscribe to this conversation on GitHub. Already have an account? Sign in.
Labels
ready-to-merge All that is left is for bors to build and merge this PR. (Remember you need to say `bors r+`.)
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants