For formulae, used Markdown math mode

doc/signatures.md

@@ -17,13 +17,13 @@ implement a dictionary. Just a few are:
 * Many, many more ....
 
 Each of these approaches has their own performance characteristics,
-memory footprints etc. For example, a table of size n with open
-addressing has no collisions and holds up to n elements, with a single
-comparison for successful lookup, and a table of size n with chaining
-and k keys has the minimum max(0, k-n) collisions and O(1 + k/n)
+memory footprints, etc. For example, a table of size $n$ with open
+addressing has no collisions and holds up to $n$ elements, with a single
+comparison for successful lookup, and a table of size $n$_ with chaining
+and $k$ keys has the minimum $\max(0, k-n)$ collisions and $\mathcal{O}(1 + k/n)$
 comparisons for lookup. While for skip lists the performance
 characteristics are about as good as that of randomly-built binary
-search trees - namely (O log n). So the choice of which to select
+search trees - namely ($\mathcal{O}(\log n)$). So the choice of which to select
 depends very much on memory available, insert/read characteristics,
 etc. So delegating the choice to a single point in your code is a very
 good idea. Unfortunately, in Erlang that's so easy to do at the moment.