[FOM] An intuitionistic query

Thomas Forster T.Forster at dpmms.cam.ac.uk
Fri Sep 11 16:41:05 EDT 2009

> For any of these interpretations, I have a related question.
> Is the following intuitive implication
>     A={a,b,c}  ==>   |A|=1 v |A|=2 v |A|=3      (**)
> intuitionistically valid?
    No, because it implies that all equations between a,b and c obey 
excluded middle.

URL:  www.dpmms.cam.ac.uk/~tf; 
DPMMS ph: +44-1223-337981; 
UEA ph:  +44-1603-592719
Cant'y office fone: x 8152
mobile in UK +44-7887-701-562; 
mobile in NZ +64-210580093.

More information about the FOM mailing list