“…In a categorical sense, it may be said therefore that both comodules and contramodules dualize the notion of module over an algebra. Even though the study of contramodules in the literature is not as developed as that of comodules, the topic has seen a lot of renewed interest in recent years (see, for instance, [2], [3], [4], [6], [17], [18], [19], [20], [25]). Accordingly, our notion of an A ∞ -contramodule over an A ∞ -coalgebra C consists of a graded vector space M ∈ V ect Z along with a collection of structure maps…”