use macro for /usr/local/plan9
diff --git a/man/man1/tbl.1 b/man/man1/tbl.1
index 0e986e9..ce13a4a 100644
--- a/man/man1/tbl.1
+++ b/man/man1/tbl.1
@@ -272,7 +272,7 @@
 .if t \{.sp3
 .1C\}
 .SH SOURCE
-.B /usr/local/plan9/src/cmd/tbl
+.B \*9/src/cmd/tbl
 .SH SEE ALSO
 .IR troff (1), 
 .IR eqn (1),