“…So i is a source of Q ′ = σ i Q = (I, H ′ , s, t), where σ i Q is the quiver by reversing the directions of all arrows in Q containing i. For any ν, ν ′ ∈ NI such that ν ′ = s i ν and I-graded K-vector spaces V, V ′ such that dim V = ν, dim V ′ = ν ′ , there exists a functor ( [21,22]) 21,22]). We have the following commutative diagram…”