`== and nan - docs accuracy?

http://pike.lysator.liu.se/generated/manual/modref/ex/predef_3A_3A/_backtick_eq_eq.html

Pike v8.0 release 3 running Hilfe v3.5 (Incremental Pike Frontend)
> `==(Math.nan, Math.nan);
(1) Result: 0
> Math.nan == Math.nan;
(2) Result: 0

This is correct behaviour per IEEE (NaN is not equal to anything,
including itself), but the docs say that == returns true "iff the two
floats are numerically equal or if both are NaN". Is this a docs bug,
or is there something else going on here?

ChrisA