Metamath Proof Explorer


Theorem liminfltlimsupex

Description: An example where the liminf is strictly smaller than the limsup . (Contributed by Glauco Siliprandi, 2-Jan-2022)

Ref Expression
Hypothesis liminfltlimsupex.1
|- F = ( n e. NN |-> if ( 2 || n , 0 , 1 ) )
Assertion liminfltlimsupex
|- ( liminf ` F ) < ( limsup ` F )

Proof

Step Hyp Ref Expression
1 liminfltlimsupex.1
 |-  F = ( n e. NN |-> if ( 2 || n , 0 , 1 ) )
2 0lt1
 |-  0 < 1
3 1 liminf10ex
 |-  ( liminf ` F ) = 0
4 1 limsup10ex
 |-  ( limsup ` F ) = 1
5 3 4 breq12i
 |-  ( ( liminf ` F ) < ( limsup ` F ) <-> 0 < 1 )
6 2 5 mpbir
 |-  ( liminf ` F ) < ( limsup ` F )