Varieties of initial dialgebras and some of their Koszul dual operads

In this paper, for a given variety $\Var$, we present a universal algorithm for constructing a subvariety of $\Var$-dialgebras from which one can recover an algebra belonging to $\Var$. Such a subvariety is called the variety of initial $\Var$-dialgebras. In addition, we construct a basis of the free initial Lie and associative dialgebras.