Entire function of exponential type
= Entire function of exponential type
{title2=$|f(z)|\le A e^{B|z|}$}
An <entire function> is of exponential type if constants $A,B>0$ give the displayed bound everywhere. A genus-zero <canonical product> with $\sum_n|a_n|^{-1}<\infty$ obeys $|\prod_n(1-z/a_n)|\le\exp(|z|\sum_n|a_n|^{-1})$, since $1+u\le e^u$ for $u\ge0$.