  In vertex algebra theory, fusion rules are described as the dimension of the
vector space of intertwining operators between three irreducible modules. We
describe fusion rules in the category of weight modules for the Weyl vertex
algebra. This way we confirm the conjecture on fusion rules based on the
Verlinde algebra. We explicitly construct intertwining operators appearing in
the formula for fusion rules. We present a result which relates irreducible
weight modules for the Weyl vertex algebra to the irreducible modules for the
affine Lie superalgebra $\widehat{gl(1 \vert 1)}$.
