  We count singular vector tuples of a system of tensors assigned to the edges
of a directed hypergraph. To do so, we study the generalisation of quivers to
directed hypergraphs. Assigning vector spaces to the nodes of a hypergraph and
multilinear maps to its hyperedges gives a hyperquiver representation.
Hyperquiver representations generalise quiver representations (where all
hyperedges are edges) and tensors (where there is only one multilinear map).
The singular vectors of a hyperquiver representation are a compatible
assignment of vectors to the nodes. We compute the dimension and degree of the
variety of singular vectors of a sufficiently generic hyperquiver
representation. Our formula specialises to known results that count the
singular vectors and eigenvectors of a generic tensor.
