Metamath Proof Explorer


Theorem lbinfle

Description: If a set of reals contains a lower bound, its infimum is less than or equal to all members of the set. (Contributed by NM, 11-Oct-2005) (Revised by AV, 4-Sep-2020)

Ref Expression
Assertion lbinfle
|- ( ( S C_ RR /\ E. x e. S A. y e. S x <_ y /\ A e. S ) -> inf ( S , RR , < ) <_ A )

Proof

Step Hyp Ref Expression
1 lbinf
 |-  ( ( S C_ RR /\ E. x e. S A. y e. S x <_ y ) -> inf ( S , RR , < ) = ( iota_ x e. S A. y e. S x <_ y ) )
2 1 3adant3
 |-  ( ( S C_ RR /\ E. x e. S A. y e. S x <_ y /\ A e. S ) -> inf ( S , RR , < ) = ( iota_ x e. S A. y e. S x <_ y ) )
3 lble
 |-  ( ( S C_ RR /\ E. x e. S A. y e. S x <_ y /\ A e. S ) -> ( iota_ x e. S A. y e. S x <_ y ) <_ A )
4 2 3 eqbrtrd
 |-  ( ( S C_ RR /\ E. x e. S A. y e. S x <_ y /\ A e. S ) -> inf ( S , RR , < ) <_ A )