Metamath Proof Explorer


Theorem ixpin

Description: The intersection of two infinite Cartesian products. (Contributed by Mario Carneiro, 3-Feb-2015)

Ref Expression
Assertion ixpin x A B C = x A B x A C

Proof

Step Hyp Ref Expression
1 anandi f Fn A x A f x B x A f x C f Fn A x A f x B f Fn A x A f x C
2 elin f x B C f x B f x C
3 2 ralbii x A f x B C x A f x B f x C
4 r19.26 x A f x B f x C x A f x B x A f x C
5 3 4 bitri x A f x B C x A f x B x A f x C
6 5 anbi2i f Fn A x A f x B C f Fn A x A f x B x A f x C
7 vex f V
8 7 elixp f x A B f Fn A x A f x B
9 7 elixp f x A C f Fn A x A f x C
10 8 9 anbi12i f x A B f x A C f Fn A x A f x B f Fn A x A f x C
11 1 6 10 3bitr4i f Fn A x A f x B C f x A B f x A C
12 7 elixp f x A B C f Fn A x A f x B C
13 elin f x A B x A C f x A B f x A C
14 11 12 13 3bitr4i f x A B C f x A B x A C
15 14 eqriv x A B C = x A B x A C