diff --git a/Old_Packages/Doc23/changes.txt b/Old_Packages/Doc23/changes.txt
index eced70476f0..68a32ec3d47 100644
--- a/Old_Packages/Doc23/changes.txt
+++ b/Old_Packages/Doc23/changes.txt
@@ -1,3 +1,6 @@
+2.20    (?? May 2001)
+- fixed typo in compare_x_at_y()
+
 2.19    (1 May 2001)
 - Fix return type of Kernel::Orientation_?.
 - angle()
diff --git a/Old_Packages/Doc23/doc_tex/kernel/Ref/compare_x_at_y.tex b/Old_Packages/Doc23/doc_tex/kernel/Ref/compare_x_at_y.tex
index cbff1462d82..e2aa9ab7cea 100644
--- a/Old_Packages/Doc23/doc_tex/kernel/Ref/compare_x_at_y.tex
+++ b/Old_Packages/Doc23/doc_tex/kernel/Ref/compare_x_at_y.tex
@@ -8,7 +8,7 @@
          of \ccStyle{p} on \ccStyle{h}%
          \ccTexHtml{ (Figure~\ref{fig-compare_x_at_y} (a))}{; see (a) in the 
          figure below}.
-         \ccPrecond \ccSytle{h} is not horizontal.}
+         \ccPrecond \ccStyle{h} is not horizontal.}
 
 \begin{ccTexOnly}
 \begin{figure}[h]
diff --git a/Packages/Kernel_23/doc_tex/kernel/Ref/compare_x_at_y.tex b/Packages/Kernel_23/doc_tex/kernel/Ref/compare_x_at_y.tex
index cbff1462d82..e2aa9ab7cea 100644
--- a/Packages/Kernel_23/doc_tex/kernel/Ref/compare_x_at_y.tex
+++ b/Packages/Kernel_23/doc_tex/kernel/Ref/compare_x_at_y.tex
@@ -8,7 +8,7 @@
          of \ccStyle{p} on \ccStyle{h}%
          \ccTexHtml{ (Figure~\ref{fig-compare_x_at_y} (a))}{; see (a) in the 
          figure below}.
-         \ccPrecond \ccSytle{h} is not horizontal.}
+         \ccPrecond \ccStyle{h} is not horizontal.}
 
 \begin{ccTexOnly}
 \begin{figure}[h]