# Is there a notation for “x is a function of y” that doesn't name the function?

I want to say that a variable $y$ is a function of $x$.

But I don't want to name the function, like:

$y = f(x)$

So is there a notation for the phrase "$y$ is a function of $x$" which does not specify a name for the function?

(A related but distinct question: Notation: is there a symbol for "not a function of"?)

• You could explicitly state the dependence of $y$ on $x$ by simply writing $y(x)$ instead of just $y$. – Edward Evans Nov 14 '16 at 22:42
• Why are you against naming the function? I don't understand how that could negatively impact anything... – JMoravitz Nov 14 '16 at 22:45
• Why do you not want to say "$y$ is a function of $x$" in words? – GEdgar Nov 14 '16 at 22:50
• It is a slight abuse of notation, but you might write $y = y(x)$ to say that $y$ depends on $x$. It is especially common to see when there are a lot of nested quantifiers and people want to highlight which parameter depends on what. – Jakub Konieczny Nov 14 '16 at 22:56
• What exactly do you mean with "$y$ is a function of $x$"? Because if you just mean "there exists a function $f$ such that $y=f(x)$", then everything is a function of $x$. For example, $42$ is a function of $x$, namely the constant function $f(x)=42$. – celtschk Nov 14 '16 at 22:59