Metamath Proof Explorer


Theorem elxp6

Description: Membership in a Cartesian product. This version requires no quantifiers or dummy variables. See also elxp4 . (Contributed by NM, 9-Oct-2004)

Ref Expression
Assertion elxp6 A B × C A = 1 st A 2 nd A 1 st A B 2 nd A C

Proof

Step Hyp Ref Expression
1 elxp4 A B × C A = dom A ran A dom A B ran A C
2 1stval 1 st A = dom A
3 2ndval 2 nd A = ran A
4 2 3 opeq12i 1 st A 2 nd A = dom A ran A
5 4 eqeq2i A = 1 st A 2 nd A A = dom A ran A
6 2 eleq1i 1 st A B dom A B
7 3 eleq1i 2 nd A C ran A C
8 6 7 anbi12i 1 st A B 2 nd A C dom A B ran A C
9 5 8 anbi12i A = 1 st A 2 nd A 1 st A B 2 nd A C A = dom A ran A dom A B ran A C
10 1 9 bitr4i A B × C A = 1 st A 2 nd A 1 st A B 2 nd A C