Metamath Proof Explorer


Theorem leadd2dd

Description: Addition to both sides of 'less than or equal to'. (Contributed by Mario Carneiro, 30-May-2016)

Ref Expression
Hypotheses leidd.1
|- ( ph -> A e. RR )
ltnegd.2
|- ( ph -> B e. RR )
ltadd1d.3
|- ( ph -> C e. RR )
leadd1dd.4
|- ( ph -> A <_ B )
Assertion leadd2dd
|- ( ph -> ( C + A ) <_ ( C + B ) )

Proof

Step Hyp Ref Expression
1 leidd.1
 |-  ( ph -> A e. RR )
2 ltnegd.2
 |-  ( ph -> B e. RR )
3 ltadd1d.3
 |-  ( ph -> C e. RR )
4 leadd1dd.4
 |-  ( ph -> A <_ B )
5 1 2 3 leadd2d
 |-  ( ph -> ( A <_ B <-> ( C + A ) <_ ( C + B ) ) )
6 4 5 mpbid
 |-  ( ph -> ( C + A ) <_ ( C + B ) )