The syntax [To-Three]() gives a page named To-Three whereas [2-3]() gives 2--3 (note the two dashes).
Is it an expected behavior of gitit?
Formatting is ok in LaTeX and in HTML as well.
Apparently, Haskell names the files according to the LaTeX convention (2--3.page instead of 2-3.page). If it is the expected behavior, it is ok!