“…IBL ∞ algebras (short for Involutive Lie Bialgebras up to coherent homotopies) were introduced in the paper [21], with applications to string topology, symplectic field theory and Lagrangian Floer theory, and have been further investigated in several other papers since then, for instance [18,57,25,39,58,41,59,22,40] We shall work with a definition of IBL ∞ algebra slightly different from, and in a certain sense dual to, the one usually appearing in the literature. More precisely, whereas IBL ∞ algebras are usually regarded as commutative BV ∞ algebras whose underlying algebras are free (see for instance [20,18,57]), we shall regard them dually as cocommutative BV ∞ coalgebras whose underlying coalgebras are cofree.…”