Metamath Proof Explorer


Theorem elixp2

Description: Membership in an infinite Cartesian product. See df-ixp for discussion of the notation. (Contributed by NM, 28-Sep-2006)

Ref Expression
Assertion elixp2 F x A B F V F Fn A x A F x B

Proof

Step Hyp Ref Expression
1 fneq1 f = F f Fn A F Fn A
2 fveq1 f = F f x = F x
3 2 eleq1d f = F f x B F x B
4 3 ralbidv f = F x A f x B x A F x B
5 1 4 anbi12d f = F f Fn A x A f x B F Fn A x A F x B
6 dfixp x A B = f | f Fn A x A f x B
7 5 6 elab2g F V F x A B F Fn A x A F x B
8 7 pm5.32i F V F x A B F V F Fn A x A F x B
9 elex F x A B F V
10 9 pm4.71ri F x A B F V F x A B
11 3anass F V F Fn A x A F x B F V F Fn A x A F x B
12 8 10 11 3bitr4i F x A B F V F Fn A x A F x B