Typo "constructive" used twice.  Replaced latter with "classical".
Add "natural in $A$ and $B$".  Build not tested.
Minor typos in case.
Swapped \PT and \BT.
"Thta" -> "That"
+"of"
Merge branch 'master' of https://github.com/byorgey/thesis
Merge pull request #10 from derekelkins/master

Minor typo fixes except for the "natural in $A$ and $B$" one.  That's debatable.