2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69262We introduce a concept of $\frac23$PROP generalizing the Kontsevich concept of $\frac12$PROP. We prove that some Stasheff-type compactification of the Kontsevich spaces $K(m,n)$ defines a topological $\frac23$PROP structure. The corresponding chain complex is a minimal model for its cohomology (both are considered as $\frac23$PROPs). We construct a $\frac23$PROP $\End(V)$ for a vector space $V$. Finally, we construct a dg Lie algebra controlling the deformations of a (co)associative bialgebra. Philosophically, this construction is a version of the Markl's operadic construction from [M1] applied to minimal models of $\frac23$PROPs.Dedicated to Borya Feigin in the occasion of his 50th birthday 17 pages, 5eps figures, latexQuantum AlgebraK-Theory and HomologyA concept of $\frac23$PROP and deformation theory of (co)associative bialgebrastext