fix index
diff --git a/doc/bn.tex b/doc/bn.tex
index 871eb74..88b1954 100644
--- a/doc/bn.tex
+++ b/doc/bn.tex
@@ -1211,7 +1211,7 @@ Which compute $c = a \odot b$ where $\odot$ is one of OR, AND or XOR.
The following four functions allow implementing arbitrary-precision two-complement numbers.
-\index{mp\_tc\_or} \index{mp\_tc\_and} \index{mp\_tc\_xor} \index {mp\_complement}\label{tcbitwiseops}
+\index{mp\_tc\_or} \index{mp\_tc\_and} \index{mp\_tc\_xor} \index{mp\_complement} \label{tcbitwiseops}
\begin{alltt}
int mp_tc_or (mp_int * a, mp_int * b, mp_int * c);
int mp_tc_and (mp_int * a, mp_int * b, mp_int * c);