On the free commutative monoid over a positive operad
Résumé
We give the explicit description of the NPL-operad structure on the free commutative monoid $\mathbf E\circ \mathbf q$ generated by a given positive operad $\mathbf q$. We propose to name NPL-operad a weak form of operad in which the nested associativity axiom is weakened down to a nested pre-Lie condition. This structure is new up to our knowledge.