Just my lucky day! (errata in The METAFONTbook)

I got this email as a reply for an errata report I sent out

thanks for your report.

I hope I am emailing the correct people for an errata I found in The MetaFont book Volume C, Page 159

yes. you've come to the right place.

Original Text

For example, Appendix B says

def --- = .. tension infinity.. enddef .

Corrected Text (It should be)

For example, Appendix B says

def --- = .. tension infinity .. enddef;

(Note the change from . to ;)

i've verified this; the reference in appendix b
is on p.262. i don't see any earlier reports on
this, so it looks like you're the first.

should this actually be the case, you will be due
a small reward. to deliver it, we'll need a
postal address. i've received word from knuth
that he expects to be looking at reports about
this time next year, so an address that will be
current at that time is what we'll need.

-- bb