Axiom ax-i2m1 6989

Description: i-squared equals -1 (expressed as i-squared plus 1 is 0). Axiom for real and complex numbers, justified by theorem axi2m1 6949. (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 6891	. . . 4 class _i
2		cmul 6894	. . . 4 class x.
3	1, 1, 2	co 5512	. . 3 class ( _i x. _i )
4		c1 6890	. . 3 class 1
5		caddc 6892	. . 3 class +
6	3, 4, 5	co 5512	. 2 class ( ( _i x. _i ) + 1 )
7		cc0 6889	. 2 class 0
8	6, 7	wceq 1243	1 wff ( ( _i x. _i ) + 1 ) = 0

This axiom is referenced by:  0cn  7019  ine0  7391  ixi  7574  inelr  7575