Axiom ax-i2m1 7918

Description: i-squared equals -1 (expressed as i-squared plus 1 is 0). Axiom for real and complex numbers, justified by Theorem axi2m1 7876. (Contributed by NM, 29-Jan-1995.)

Assertion

Ref	Expression
ax-i2m1	|- ( ( _i x. _i ) + 1 ) = 0

Detailed syntax breakdown of Axiom ax-i2m1

Step	Hyp	Ref	Expression
1		ci 7815	. . . 4 class _i
2		cmul 7818	. . . 4 class x.
3	1, 1, 2	co 5877	. . 3 class ( _i x. _i )
4		c1 7814	. . 3 class 1
5		caddc 7816	. . 3 class +
6	3, 4, 5	co 5877	. 2 class ( ( _i x. _i ) + 1 )
7		cc0 7813	. 2 class 0
8	6, 7	wceq 1353	1 wff ( ( _i x. _i ) + 1 ) = 0

This axiom is referenced by:  0cn  7951  ine0  8353  ixi  8542  inelr  8543