Metamath Proof Explorer


Theorem relogbexpd

Description: Identity law for general logarithm: the logarithm of a power to the base is the exponent, a deduction version. (Contributed by metakunt, 22-May-2024)

Ref Expression
Hypotheses relogbexpd.1
|- ( ph -> B e. RR+ )
relogbexpd.2
|- ( ph -> B =/= 1 )
relogbexpd.3
|- ( ph -> M e. ZZ )
Assertion relogbexpd
|- ( ph -> ( B logb ( B ^ M ) ) = M )

Proof

Step Hyp Ref Expression
1 relogbexpd.1
 |-  ( ph -> B e. RR+ )
2 relogbexpd.2
 |-  ( ph -> B =/= 1 )
3 relogbexpd.3
 |-  ( ph -> M e. ZZ )
4 1 2 3 3jca
 |-  ( ph -> ( B e. RR+ /\ B =/= 1 /\ M e. ZZ ) )
5 relogbexp
 |-  ( ( B e. RR+ /\ B =/= 1 /\ M e. ZZ ) -> ( B logb ( B ^ M ) ) = M )
6 4 5 syl
 |-  ( ph -> ( B logb ( B ^ M ) ) = M )