diff -r d5caffd01b72 -r 61541264d4b3 text/basic_properties.tex
--- a/text/basic_properties.tex	Thu Aug 11 13:26:00 2011 -0700
+++ b/text/basic_properties.tex	Thu Aug 11 13:54:38 2011 -0700
@@ -90,7 +90,7 @@
 $r$ be the restriction of $b$ to $X\setminus S$.
 Note that $S$ is a disjoint union of balls.
 Assign to $b$ the acyclic (in positive degrees) subcomplex $T(b) \deq r\bullet\bc_*(S)$.
-Note that if a diagram $b'$ is part of $\bd b$ then $T(B') \sub T(b)$.
+Note that if a diagram $b'$ is part of $\bd b$ then $T(b') \sub T(b)$.
 Both $f$ and the identity are compatible with $T$ (in the sense of acyclic models, \S\ref{sec:moam}), 
 so $f$ and the identity map are homotopic.
 \end{proof}