use macro for /usr/local/plan9
diff --git a/man/man1/kill.1 b/man/man1/kill.1
index c7d5ff9..5719f16 100644
--- a/man/man1/kill.1
+++ b/man/man1/kill.1
@@ -63,7 +63,7 @@
 .B CONT
 signal.
 .SH SOURCE
-.B /usr/local/plan9/bin
+.B \*9/bin
 .SH "SEE ALSO"
 .IR ps (1),
 .IR notify (3)