  If $\phi$ is an automorphism of a group $G$ and $x,y\in G$, we say that $x$
and $y$ are $\phi$-twisted conjugates if there exists an $z\in G$ such that
$y=z.x.\phi(z^{-1})$. This is an equivalence relation. If there are infinitely
many $\phi$-twisted conjugacy classes for every automorphism $\phi$ of $G$ we
say that $G$ has the $R_\infty$-property. We prove that the generalized Richard
Thompson groups $F_n$ and $F(l,A,P)$ have the $R_\infty$-property.
