Definition df-ni 9694

Description: Define the class of positive integers. This is a "temporary" set used in the construction of complex numbers df-c 9942, and is intended to be used only by the construction. (Contributed by NM, 15-Aug-1995.) (New usage is discouraged.)

Assertion

Ref	Expression
df-ni	|- N. = ( om \ { (/) } )

Detailed syntax breakdown of Definition df-ni

Step	Hyp	Ref	Expression
1		cnpi 9666	. 2 class N.
2		com 7065	. . 3 class om
3		c0 3915	. . . 4 class (/)
4	3	csn 4177	. . 3 class { (/) }
5	2, 4	cdif 3571	. 2 class ( om \ { (/) } )
6	1, 5	wceq 1483	1 wff N. = ( om \ { (/) } )

This definition is referenced by:  elni  9698  pinn  9700  niex  9703  ltsopi  9710  dmaddpi  9712  dmmulpi  9713  wuncn  9991