r:Rng, e:|r|. (1 r e) = e 

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Up	rings 1
Definitions of Statement	Rng, r+gp, n r e
Definitions	t  T, IMonoid, x:A. B(x), t.1, , P & Q, Mon, Group{i}, AbGrp, r+gp, |g|, n r e
Lemmas	rng wf, abgrp wf, grp id wf, grp op wf, grp car wf, monoid p wf, add grp of rng wf b, mon nat op one