diff --git a/man3/casin.3 b/man3/casin.3
index f5c191e1f..03037f999 100644
--- a/man3/casin.3
+++ b/man3/casin.3
@@ -1,7 +1,7 @@
 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
 .\" Distributed under GPL
 .\"
-.TH CASIN 3 2002-07-28 "" "Linux Programmer's Manual"
+.TH CASIN 3 2007-12-26 "" "Linux Programmer's Manual"
 .SH NAME
 casin, casinf, casinl \- complex arc sine
 .SH SYNOPSIS
@@ -17,12 +17,18 @@ Link with \fI\-lm\fP.
 .SH DESCRIPTION
 The
 .BR casin ()
-function calculates the complex asin(3).
-If y = casin(z), then z = csin(y).
-The real part of y is chosen in the interval [\-pi/2,pi/2].
+function calculates the complex arc sine of
+.IR z .
+If \fIy\ =\ casin(z)\fP, then \fIz\ =\ csin(y)\fP.
+The real part of
+.I y
+is chosen in the interval [\-pi/2,pi/2].
 .LP
-One has
-casin(z) = \-i clog(iz + csqrt(1 \- z * z)).
+One has:
+.nf
+
+    casin(z) = \-i clog(iz + csqrt(1 \- z * z))
+.fi
 .SH "CONFORMING TO"
 C99
 .SH "SEE ALSO"
diff --git a/man3/catan.3 b/man3/catan.3
index 926b669ee..4ffcc015f 100644
--- a/man3/catan.3
+++ b/man3/catan.3
@@ -1,7 +1,7 @@
 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
 .\" Distributed under GPL
 .\"
-.TH CATAN 3 2002-07-28 "" "Linux Programmer's Manual"
+.TH CATAN 3 2007-12-26 "" "Linux Programmer's Manual"
 .SH NAME
 catan, catanf, catanl \- complex arc tangents
 .SH SYNOPSIS
@@ -17,12 +17,16 @@ Link with \fI\-lm\fP.
 .SH DESCRIPTION
 The
 .BR catan ()
-function calculates the complex atan(3).
-If y = catan(z), then z = ctan(y).
+function calculates the complex arc tangent of
+.IR z .
+If \fIy\ =\ catan(z)\fP, then \fIz\ =\ ctan(y)\fP.
 The real part of y is chosen in the interval [\-pi/2,pi/2].
 .LP
-One has
-catan(z) = 1 / 2i clog((1 + iz) / (1 \- iz)).
+One has:
+.nf
+
+    catan(z) = 1 / 2i clog((1 + iz) / (1 \- iz))
+.fi
 .SH "CONFORMING TO"
 C99
 .SH "SEE ALSO"