Metamath Proof Explorer


Theorem cxpge0d

Description: Nonnegative exponentiation with a real exponent is nonnegative. (Contributed by Mario Carneiro, 30-May-2016)

Ref Expression
Hypotheses recxpcld.1 ( 𝜑𝐴 ∈ ℝ )
recxpcld.2 ( 𝜑 → 0 ≤ 𝐴 )
recxpcld.3 ( 𝜑𝐵 ∈ ℝ )
Assertion cxpge0d ( 𝜑 → 0 ≤ ( 𝐴𝑐 𝐵 ) )

Proof

Step Hyp Ref Expression
1 recxpcld.1 ( 𝜑𝐴 ∈ ℝ )
2 recxpcld.2 ( 𝜑 → 0 ≤ 𝐴 )
3 recxpcld.3 ( 𝜑𝐵 ∈ ℝ )
4 cxpge0 ( ( 𝐴 ∈ ℝ ∧ 0 ≤ 𝐴𝐵 ∈ ℝ ) → 0 ≤ ( 𝐴𝑐 𝐵 ) )
5 1 2 3 4 syl3anc ( 𝜑 → 0 ≤ ( 𝐴𝑐 𝐵 ) )