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(*  Reflected boolean property and morphic image, injection, bijection *)
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Section MorphicImage.
Variables aT rT : finGroupType.
Variables (D : {group aT}) (f : {morphism D >-> rT}) (x : aT).
Hypothesis Dx : x \in D.

Lemma quotient_cycle x H : x \in 'N(H) -> <[x]> / H = <[coset H x]>.