[cokernel_hacker]

Interesting. One issue is treatment of 1 / -inf. This would be -0 in traditional IEEE 754 but would now be +0 IIUC.

This would imply that 1 / (1 / -inf) would now be +inf instead of -inf.

[thechao]

0 is unsigned. I would reject 1/inf — it would be NAN. If the user wants to play silly games with derivatives, computer algebra systems are that way: —>.

[piadodjanho]

NaN is NaR (not a real) in posit notation.