May I suggest the following tiny patch, on the basis that it is more
instructive than changing the second '12' to a '13'?

	Hugh
	hgs / dmu.ac.uk

--- ruby-man-1.4/syntax.html    Wed Jun 14 12:17:48 2000
+++ ruby-man-1.4/syntax2.html   Thu Jun 22 12:13:41 2000
@@ -1195,6 +1195,7 @@
        when 7 .. 12
          "child"
        when 12 .. 18
+          # Note: 12 already matched by "child"
          "youth"
        else
          "adult"