Theorem cjcji

Description: The conjugate of the conjugate is the original complex number. Proposition 10-3.4(e) of Gleason p. 133. (Contributed by NM, 11-May-1999)

	Ref	Expression
Hypothesis	recl.1	|- A e. CC
Assertion	cjcji	|- ( * ` ( * ` A ) ) = A

Proof

Step	Hyp	Ref	Expression
1		recl.1	|- A e. CC
2		cjcj	|- ( A e. CC -> ( * ` ( * ` A ) ) = A )
3	1 2	ax-mp	|- ( * ` ( * ` A ) ) = A