Question: I want to do something like that:

```
var result = genericList.ToDictionary(CalculateSomething(x => x.Date), y => y.Point);

```

So according with that example i want to call `CalculateSomething()` inside `.ToDictionary()`

is there any ways i can do that, i may do that through `foreach` loop but i would like to keep `linq` syntax.

Answer: 
The [exact definition](http://www.w3.org/TR/html4/intro/sgmltut.html#h-3.3.4.2) is:

> 
> Some attributes play the role of boolean variables (e.g., the selected
>  attribute for the OPTION element). Their **appearance** in the start tag
>  of an element implies that the value of the attribute is "true". Their
>  **absence** implies a value of "false".
> 
> 
> 

Also:

> 
> Boolean attributes **may** legally take a single value: the name of the attribute itself [...] In HTML, boolean attributes **may** appear in minimized form
> 
> 
> 

Basically, this implies that there are only two possible statuses for boolean attributes, true and false, but there isn't a *not set* status.
Readability, a lot of HTML is not coded by people with computer science backgrounds so the concept of "Boolean" would be foreign to them in those terms. Also it improves readability for Computer Science and other technical users by providing reinforced clues as to the function of a given statement.