Description: The Cartesian product of two sets is a set. Proposition 6.2 of TakeutiZaring p. 23. (Contributed by NM, 14-Aug-1994)
Ref | Expression | ||
---|---|---|---|
Hypotheses | xpex.1 | |- A e. _V |
|
xpex.2 | |- B e. _V |
||
Assertion | xpex | |- ( A X. B ) e. _V |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xpex.1 | |- A e. _V |
|
2 | xpex.2 | |- B e. _V |
|
3 | xpexg | |- ( ( A e. _V /\ B e. _V ) -> ( A X. B ) e. _V ) |
|
4 | 1 2 3 | mp2an | |- ( A X. B ) e. _V |