"Except" in predicate logic

Question

I have a phrase that I am trying to translate into predicate logic. The phrase is as follows:

All lions except old ones roar

So far I have written down that:

$∀x((L(x) \land \lnot O(x)) \to R(x))$

Where $L(x)$ is "$x$ is a lion", $O(x)$ is "$x$ is old", and $R(x)$ is "$x$ roars". I am wondering if this is correct notation. I am mostly confused about the "except" in the phrase because as I have translated states that all lions who are not old roar.

Does any one have any thoughts about the notation for this phrase?

Answer 1

∀x(L(x)∧¬O(x)→R(x))
says all lions that are not old roar.

To render the except requires more:
∀x(L(x)∧¬O(x)→R(x)) ∧ ∀x(L(x)∧O(x)→¬R(x))

Answer 2

I think this also works (assuming that except means that old lions do not roar): $$\forall x\,\Big[L(x)\rightarrow\big(\neg O(x)\leftrightarrow R(x)\big)\Big]\,.$$