Nicer O() function.

book/math_prequisites.tex

@@ -43,7 +43,7 @@ factors are contained in $\factorBase$.
 
 
 \section{Algorithmic Complexity Notation}
-The notation used to describe asymptotic complexity follows the $O$-notation,
+The notation used to describe asymptotic complexity follows the $\mathcal{O}$-notation,
 abused under the conventions and limits of MIT's Introduction to Algorithms
 \cite{MITalg}.
 

book/question_authority.tex

@@ -46,7 +46,7 @@
 \newcommand{\naturalPrime}{\mathbb{P}}
 \newcommand{\integerZ}{\mathbb{Z}}
 \newcommand{\factorBase}{\mathcal{B}}
-\newcommand{\bigO}[1]{\ensuremath{\operatorname{O}\left(#1\right)}}
+\newcommand{\bigO}[1]{\ensuremath{\mathcal{O}\left(#1\right)}}
 \newcommand{\openssl}{\textsc{OpenSSL}\ }
 %% here adopting Wikipedia's notation <https://en.wikipedia.org/wiki/Isqrt>
 \newcommand{\dsqrt}[1]{\ensuremath{isqrt(#1)}}