K -> D

Thanks to Anonymous
https://stacks.math.columbia.edu/tag/05TD#comment-7814

derived.tex

@@ -5526,7 +5526,7 @@ \section{Higher derived functors}
 By
 Lemma \ref{lemma-derived-canonical-delta-functor}
 we obtain a distinguished triangle
-$(A[0], B[0], C[0], a, b, c)$ in $K^{+}(\mathcal{A})$.
+$(A[0], B[0], C[0], a, b, c)$ in $D^{+}(\mathcal{A})$.
 From the long exact cohomology sequence (and the vanishing for $i < 0$
 proved above) we deduce that $0 \to R^0F(A) \to R^0F(B) \to R^0F(C)$
 is exact. Hence $R^0F$ is left exact. Of course this also proves that if