Exactly one in Predicate Logic

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Could anyone tell me how to translate the following sentence into predicate logic.

E : the set of elephants

A : the set of animals

G(x) : x is green

E(x) : x is an elephant

N(x; y) : name of x is y

There is exactly one green elephant and his name is James.

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For example $$\exists j\;\Bigl( E(j)\land G(j)\land\forall x\; \bigl((E(x)\land G(x))\to (x=j\land N(x,\text{James}))\bigr)\Bigr) $$ ("There exists an object $j$ that is both an elephant and green and any (other) object that is also an elephant and green is this $j$ and is named James") or $$\exists j\;\Bigl( E(j)\land G(j)\land N(j,\text{James})\land\forall x\; \bigl((E(x)\land G(x))\to x=j\bigr)\Bigr) $$ ("There exists a green elephant named James and any green elephant equals this") or if $\exists !$ is available $$ \bigl(\exists!x\,E(x)\land G(x)\bigr)\land \forall x\,\bigl((E(x)\land G(x))\to N(x,\text{James})\bigr)$$ ("There exists exactly one green elephant and all a green elephants are named James").

Note that $$ \exists !j\;\bigl(E(j)\land G(j)\land N(j,\text{James})\bigr)$$ is not correct