Official upstream source

MulAction.sum_card_fixedBy_eq_card_orbits_mul_card_group

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Package: mathlib
Repository: https://github.com/leanprover-community/mathlib4
Commit: 5e932f97dd25535344f80f9dd8da3aab83df0fe6
Source path: Mathlib/GroupTheory/GroupAction/Quotient.lean:262
SHA-256: sha256:50fc92cfeb4c8df97539ecbe4e6153518bea82afe6da61d531f92a9c0170ebb0
Verified bytes: 22,247

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