In this chapter, we conclude our discussion of homological aspects of logarithmic deformation theory by proving the two abstract unobstructedness theorems announced in the previous chapter. As a means to do so, we also introduce a third extended Maurer–Cartan equation which we call the “quantum extended Maurer–Cartan equation.” The proofs follow an article of Chan, Leung, and Ma, who in turn followed ideas of Katzarkov, Kontsevich, and Pantev as well as Terilla.