Metamath Proof Explorer


Theorem flleceil

Description: The floor of a real number is less than or equal to its ceiling. (Contributed by AV, 30-Nov-2018)

Ref Expression
Assertion flleceil
|- ( A e. RR -> ( |_ ` A ) <_ ( |^ ` A ) )

Proof

Step Hyp Ref Expression
1 reflcl
 |-  ( A e. RR -> ( |_ ` A ) e. RR )
2 id
 |-  ( A e. RR -> A e. RR )
3 ceilcl
 |-  ( A e. RR -> ( |^ ` A ) e. ZZ )
4 3 zred
 |-  ( A e. RR -> ( |^ ` A ) e. RR )
5 flle
 |-  ( A e. RR -> ( |_ ` A ) <_ A )
6 ceilge
 |-  ( A e. RR -> A <_ ( |^ ` A ) )
7 1 2 4 5 6 letrd
 |-  ( A e. RR -> ( |_ ` A ) <_ ( |^ ` A ) )