Composition Diamond lemma for Lie algebra over a field $F$ has already been investigated in several papers :
L.Bokut and Y.Q.Chen Groebner-Shirshov bases for LirLie algebras
and
A.I Shirshov, Some algorithmic problems for Lie algebras
I am looking for a paper including composition lemma for the case of Leibniz algebras? I appreciate your comments and your time in advance.