[Mehrbod]

A well-known, but here anonymous, philosopher was delivering
a talk on linguistics and had just stated that the
double negative construction in some languages has a positive
meaning and in some a (very) negative meaning. He
went on to observe, however, that in no language was it the
case that a double positive construction has a negative meaning.
To this another well-known philosopher in the rear of
the lecture room responded with a jeering "yeah, yeah."