Theorem mircinv

Description: The center point is invariant of a point inversion. (Contributed by Thierry Arnoux, 25-Aug-2019)

	Ref	Expression
Hypotheses	mirval.p	|- P = ( Base ` G )
	mirval.d	|- .- = ( dist ` G )
	mirval.i	|- I = ( Itv ` G )
	mirval.l	|- L = ( LineG ` G )
	mirval.s	|- S = ( pInvG ` G )
	mirval.g	|- ( ph -> G e. TarskiG )
	mirval.a	|- ( ph -> A e. P )
	mirfv.m	|- M = ( S ` A )
Assertion	mircinv	|- ( ph -> ( M ` A ) = A )

Proof

Step	Hyp	Ref	Expression
1		mirval.p	|- P = ( Base ` G )
2		mirval.d	|- .- = ( dist ` G )
3		mirval.i	|- I = ( Itv ` G )
4		mirval.l	|- L = ( LineG ` G )
5		mirval.s	|- S = ( pInvG ` G )
6		mirval.g	|- ( ph -> G e. TarskiG )
7		mirval.a	|- ( ph -> A e. P )
8		mirfv.m	|- M = ( S ` A )
9		eqid	|- A = A
10	1 2 3 4 5 6 7 8 7	mirinv	|- ( ph -> ( ( M ` A ) = A <-> A = A ) )
11	9 10	mpbiri	|- ( ph -> ( M ` A ) = A )