Example 75.19.5. Let $S$ be a scheme. Let $X$ be a quasi-compact and quasi-separated algebraic space over $S$. Let $(\mathcal{F}_ n)$ be an inverse system of quasi-coherent sheaves on $X$. Since $DQ_ X$ is a right adjoint it commutes with products and therefore with derived limits. Hence we see that
where the first $R\mathop{\mathrm{lim}}\nolimits $ is taken in $D(\mathcal{O}_ X)$. In fact, let's write $K = R\mathop{\mathrm{lim}}\nolimits \mathcal{F}_ n$ for this. For any affine $U$ étale over $X$ we have
since cohomology commutes with derived limits and since the quasi-coherent sheaves $\mathcal{F}_ n$ have no higher cohomology on affines. By the computation of $R\mathop{\mathrm{lim}}\nolimits $ in the category of abelian groups, we see that $H^ i(U, K) = 0$ unless $i \in [0, 1]$. Then finally we conclude that the $R\mathop{\mathrm{lim}}\nolimits $ in $D_\mathit{QCoh}(\mathcal{O}_ X)$, which is $DQ_ X(K)$ by the above, is in $D^ b_\mathit{QCoh}(\mathcal{O}_ X)$ and has vanishing cohomology sheaves in negative degrees by Lemma 75.19.4.
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