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[Merged by Bors] - feat(category_theory/preadditive): Schur's lemma #7366
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π Great news! Looks like all the dependencies have been resolved:
π‘ To add or remove a dependency please update this issue/PR description. Brought to you by Dependent Issues (:robot: ). Happy coding! |
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LGTM, although I don't know much about the category theory library so I'll ask a second reviewer.
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Thanks π
bors merge
We prove Schur's lemma for `π`-linear categories with finite dimensional hom spaces, over an algebraically closed field `π`: the hom space `X βΆ Y` between simple objects `X` and `Y` is at most one dimensional, and is 1-dimensional iff `X` and `Y` are isomorphic. Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Pull request successfully merged into master. Build succeeded: |
In fact, we've had Schur's lemma in mathlib for over a year, since #7366, but this was stated very abstractly: for any linear category over an algebraically closed field with finite dimensional hom spaces, and kernels. Finally, `fdRep k G` satisfies all those hypotheses, so we can use Schur's lemma! Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
We prove Schur's lemma for
π
-linear categories with finite dimensional hom spaces,over an algebraically closed field
π
:the hom space
X βΆ Y
between simple objectsX
andY
is at most one dimensional,and is 1-dimensional iff
X
andY
are isomorphic.