T is a simple first order theory as defined by Shelah. $M$ is a model of $T$. I write $acl^n(A)$ for the set of elements in $M$ lying in a finite $A$-definable set of size at most $n$. If $a$ and $b$ are independant, does the following equality hold? $$acl^n(a)\cap acl^n(b)=acl^n(\emptyset)$$