The fusion process where a and b fuse into c corresponds to a N a b c dimensional complex vector space V a b c , consisting of all the distinct orthonormal quantum states in which a and b fuse into c . This forms a Hilbert space. When N a b c ≤ ≤ 1 , such as in the Ising and Fibonacci examples, V a b c is at most just a one dimensional space with one state. The direct sum ⨁ ⨁ c V a b c is a decomposition of H a ⊗ ⊗ H b the tensor product of the Hilbert space of individual anyon a and the Hilbert space of individual anyon b . In topological quantum field theory, V a b c is the vector space associated with the pair of pants with waist labeled c and legs a and b .