Metamath Proof Explorer


Theorem ltexp1dd

Description: Raising both sides of 'less than' to the same positive integer preserves ordering. (Contributed by Steven Nguyen, 24-Aug-2023)

Ref Expression
Hypotheses ltexp1d.1
|- ( ph -> A e. RR+ )
ltexp1d.2
|- ( ph -> B e. RR+ )
ltexp1d.3
|- ( ph -> N e. NN )
ltexp1dd.4
|- ( ph -> A < B )
Assertion ltexp1dd
|- ( ph -> ( A ^ N ) < ( B ^ N ) )

Proof

Step Hyp Ref Expression
1 ltexp1d.1
 |-  ( ph -> A e. RR+ )
2 ltexp1d.2
 |-  ( ph -> B e. RR+ )
3 ltexp1d.3
 |-  ( ph -> N e. NN )
4 ltexp1dd.4
 |-  ( ph -> A < B )
5 1 2 3 ltexp1d
 |-  ( ph -> ( A < B <-> ( A ^ N ) < ( B ^ N ) ) )
6 4 5 mpbid
 |-  ( ph -> ( A ^ N ) < ( B ^ N ) )