Element orders in a finite quotient occur in the original group

ID: element-orders-in-a-finite-quotient-occur-in-the-original-group

Let be a finite group and a surjective group homomorphism. Choose a preimage of . Since , the order of a group element divides ; write . Then has order , because holds exactly when , or equivalently . This proves existence of an element of order in . It need not be a preimage of : for the quotient map , both preimages of the nonidentity target element have order , while the order- element of the source maps to zero. Thus the assertion concerns element-order existence, not splitting of the quotient map.

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