Metamath Proof Explorer


Theorem xpsnen2g

Description: A set is equinumerous to its Cartesian product with a singleton on the left. (Contributed by Stefan O'Rear, 21-Nov-2014)

Ref Expression
Assertion xpsnen2g
|- ( ( A e. V /\ B e. W ) -> ( { A } X. B ) ~~ B )

Proof

Step Hyp Ref Expression
1 snex
 |-  { A } e. _V
2 xpcomeng
 |-  ( ( { A } e. _V /\ B e. W ) -> ( { A } X. B ) ~~ ( B X. { A } ) )
3 1 2 mpan
 |-  ( B e. W -> ( { A } X. B ) ~~ ( B X. { A } ) )
4 xpsneng
 |-  ( ( B e. W /\ A e. V ) -> ( B X. { A } ) ~~ B )
5 4 ancoms
 |-  ( ( A e. V /\ B e. W ) -> ( B X. { A } ) ~~ B )
6 entr
 |-  ( ( ( { A } X. B ) ~~ ( B X. { A } ) /\ ( B X. { A } ) ~~ B ) -> ( { A } X. B ) ~~ B )
7 3 5 6 syl2an2
 |-  ( ( A e. V /\ B e. W ) -> ( { A } X. B ) ~~ B )