RE: [css-variables] CSS Variables are a NEW kind of variable

[François REMY:] 
> > The very idea of mixing up a function with a name ('define') is
> > completely confusing.
> 
> +1, BTW.
> 
All right, just so I understand what was being talked about. What part
of the following included/'mixed up' a "function"? 

	:root { define-link-color: blue }
	a { color: $link-color }

I see a user-defined property set to a value. And a delimiter to dereference/use 
that user-defined property. We're clearly not talking about the CSS function 
syntax since there is no such thing here so what are we referring to?