Axiom ax-i2m1 7891

Description: i-squared equals -1 (expressed as i-squared plus 1 is 0). Axiom for real and complex numbers, justified by Theorem axi2m1 7849. (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 7788	. . . 4 class _i
2		cmul 7791	. . . 4 class x.
3	1, 1, 2	co 5865	. . 3 class ( _i x. _i )
4		c1 7787	. . 3 class 1
5		caddc 7789	. . 3 class +
6	3, 4, 5	co 5865	. 2 class ( ( _i x. _i ) + 1 )
7		cc0 7786	. 2 class 0
8	6, 7	wceq 1353	1 wff ( ( _i x. _i ) + 1 ) = 0

This axiom is referenced by:  0cn  7924  ine0  8325  ixi  8514  inelr  8515