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Metamath Proof Explorer

Theorem letop

Description: The topology of the extended reals. (Contributed by Mario Carneiro, 3-Sep-2015)

Ref Expression
Assertion letop 
|- ( ordTop ` <_ ) e. Top

Proof

Step Hyp Ref Expression
1 letopon 
 |-  ( ordTop ` <_ ) e. ( TopOn ` RR* )
2 1 topontopi 
 |-  ( ordTop ` <_ ) e. Top