Metamath Proof Explorer


Theorem brcart

Description: Binary relation form of the cartesian product operator. (Contributed by Scott Fenton, 11-Apr-2014) (Revised by Mario Carneiro, 19-Apr-2014)

Ref Expression
Hypotheses brcart.1 A V
brcart.2 B V
brcart.3 C V
Assertion brcart A B 𝖢𝖺𝗋𝗍 C C = A × B

Proof

Step Hyp Ref Expression
1 brcart.1 A V
2 brcart.2 B V
3 brcart.3 C V
4 opex A B V
5 df-cart 𝖢𝖺𝗋𝗍 = V × V × V ran V E pprod E E V
6 1 2 opelvv A B V × V
7 brxp A B V × V × V C A B V × V C V
8 6 3 7 mpbir2an A B V × V × V C
9 3anass x = y z y E A z E B x = y z y E A z E B
10 1 epeli y E A y A
11 2 epeli z E B z B
12 10 11 anbi12i y E A z E B y A z B
13 12 anbi2i x = y z y E A z E B x = y z y A z B
14 9 13 bitri x = y z y E A z E B x = y z y A z B
15 14 2exbii y z x = y z y E A z E B y z x = y z y A z B
16 vex x V
17 16 1 2 brpprod3b x pprod E E A B y z x = y z y E A z E B
18 elxp x A × B y z x = y z y A z B
19 15 17 18 3bitr4ri x A × B x pprod E E A B
20 4 3 5 8 19 brtxpsd3 A B 𝖢𝖺𝗋𝗍 C C = A × B