Lemma 22.19.10. Let $R$ be a ring. Let $\mathcal{A}$ be a differential graded category over $R$. Let $x$ be an object of $\mathcal{A}$. Let

$(E, \text{d}) = \mathop{\mathrm{Hom}}\nolimits _\mathcal {A}(x, x)$

be the differential graded $R$-algebra of endomorphisms of $x$. We obtain a functor

$\mathcal{A} \longrightarrow \text{Mod}^{dg}_{(E, \text{d})},\quad y \longmapsto \mathop{\mathrm{Hom}}\nolimits _\mathcal {A}(x, y)$

of differential graded categories by letting $E$ act on $\mathop{\mathrm{Hom}}\nolimits _\mathcal {A}(x, y)$ via composition in $\mathcal{A}$. This functor induces functors

$\text{Comp}(\mathcal{A}) \to \text{Mod}_{(A, \text{d})} \quad \text{and}\quad K(\mathcal{A}) \to K(\text{Mod}_{(A, \text{d})})$

by an application of Lemma 22.19.5.

Proof. This lemma proves itself. $\square$

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