Description: Reverse closure for the second argument of pGrp . (Contributed by Mario Carneiro, 15-Jan-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | pgpgrp | |- ( P pGrp G -> G e. Grp ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid | |- ( Base ` G ) = ( Base ` G ) |
|
2 | eqid | |- ( od ` G ) = ( od ` G ) |
|
3 | 1 2 | ispgp | |- ( P pGrp G <-> ( P e. Prime /\ G e. Grp /\ A. x e. ( Base ` G ) E. n e. NN0 ( ( od ` G ) ` x ) = ( P ^ n ) ) ) |
4 | 3 | simp2bi | |- ( P pGrp G -> G e. Grp ) |