Metamath Proof Explorer


Theorem tpr2uni

Description: The usual topology on ( RR X. RR ) is the product topology of the usual topology on RR . (Contributed by Thierry Arnoux, 21-Sep-2017)

Ref Expression
Hypothesis tpr2tp.0
|- J = ( topGen ` ran (,) )
Assertion tpr2uni
|- U. ( J tX J ) = ( RR X. RR )

Proof

Step Hyp Ref Expression
1 tpr2tp.0
 |-  J = ( topGen ` ran (,) )
2 1 tpr2tp
 |-  ( J tX J ) e. ( TopOn ` ( RR X. RR ) )
3 2 toponunii
 |-  ( RR X. RR ) = U. ( J tX J )
4 3 eqcomi
 |-  U. ( J tX J ) = ( RR X. RR )