Definition df-in 3213

Description: Define the intersection of two classes. See elin 3219 for membership. (Contributed by SF, 10-Jan-2015.)

Assertion

Ref	Expression
df-in	|- (A i^i B) = ∼ (A &ncap B)

Detailed syntax breakdown of Definition df-in

Step	Hyp	Ref	Expression
1		cA	. . 3 class A
2		cB	. . 3 class B
3	1, 2	cin 3208	. 2 class (A i^i B)
4	1, 2	cnin 3204	. . 3 class (A &ncap B)
5	4	ccompl 3205	. 2 class ∼ (A &ncap B)
6	3, 5	wceq 1642	1 wff (A i^i B) = ∼ (A &ncap B)

This definition is referenced by:  elin  3219  nfin  3230  difeq1  3246  difeq2  3247  dfin5  3545  incompl  4073  inexg  4100