** A Remark on Vanishing of Chain Complexes **

*Yuji Yoshino*

**Abstract**

For chain complexes *X* ∈ *D*(*R*) in the derived category over a commutative noetherian ring *R*, we prove that RHom_{ R }(*W*, *X*) = 0 if and only if *W* ^{L}⊗_{ R } *X* = 0.