"min" and "max"

[pascal111]

On Tuesday, 9 August 2022 at 23:56:53 UTC, Paul Backus wrote:
> On Tuesday, 9 August 2022 at 23:35:23 UTC, pascal111 wrote:
>> "min" and "max" in "std.algorithm" can be used with single 
>> values to pick up the min and max values, but it didn't 
>> mention how they can be used with ranges in the documentation:
>>
>> https://dlang.org/phobos/std_algorithm_comparison.html#.min
>
> The docs do mention `minElement` and `maxElement` (the range 
> versions) under the "See Also" heading, but you're right that 
> it's not super clear *why* they're mentioned.

They said " If at least one of the arguments is NaN, the result 
is an unspecified value. See std.algorithm.searching.minElement 
for examples on how to cope with NaNs.", as a beginner how can I 
guess what "NaNs" means or if it refers to ranges?!