A double exponential function is a constant raised to a power of a Exponential Function; EG: f ( x ) = a b x 𝑓 𝑥 superscript 𝑎 superscript 𝑏 𝑥 f(x)=a^{b^{x}} for a > 1 , b > 1 formulae-sequence 𝑎 1 𝑏 1 a>1,b>1 .