[Python-Dev] Why is nan != nan? (original) (raw)

Greg Ewing greg.ewing at canterbury.ac.nz
Fri Mar 26 03:25:30 CET 2010

Curt Hagenlocher wrote:

Wait, what? I haven't been paying much attention, but this is backwards. There are multiple representations of NaN in the IEEE encoding;

I think Nick's point is that there aren't enough bits to give the result of every operation its own unique NaN.

The payload of a NaN in typical hardware implementations is quite small, because it has to fit into the exponent field.

-- Greg