Metamath Proof Explorer


Theorem rpexpcld

Description: Closure law for exponentiation of positive reals. (Contributed by Mario Carneiro, 28-May-2016)

Ref Expression
Hypotheses rpexpcld.1
|- ( ph -> A e. RR+ )
rpexpcld.2
|- ( ph -> N e. ZZ )
Assertion rpexpcld
|- ( ph -> ( A ^ N ) e. RR+ )

Proof

Step Hyp Ref Expression
1 rpexpcld.1
 |-  ( ph -> A e. RR+ )
2 rpexpcld.2
 |-  ( ph -> N e. ZZ )
3 rpexpcl
 |-  ( ( A e. RR+ /\ N e. ZZ ) -> ( A ^ N ) e. RR+ )
4 1 2 3 syl2anc
 |-  ( ph -> ( A ^ N ) e. RR+ )