problem with isnan

[John C via Digitalmars-d-learn]

On Friday, 11 November 2016 at 20:55:52 UTC, Charles Hixson wrote:
> Thank you.  Unfortunately:
> import    std.math;
>         ...
>     assert    (isNan (c.curActivation), "cell has unexpected 
> curActivation: %s".format(c.curActivation));
>
> yields:
> cell.d(292): Error: undefined identifier 'isNan', did you mean 
> overloadset 'isnan'?

It should be isNaN.