Re: On writing negative zero - with or without sign

You might erroneously propagate the error using

dz**2 = dx**2 + dy**2

for the case

z = x + y

the error being due to the fact that x and y are anticorrelated. How is
interval arithmetic going to know that?

Actually that is the UNcorrelated case, for ANTIcorrelated you would use

dz = |dx - dy|
.