“…In this paper we extend the duality network of 4d N = 4, 3d N = 4 and 2d N = (0, 4) gauge theories [31,32] by examining half-BPS N = (0, 4) boundary conditions in 3d N = 4 gauge theories that can be constructed from the brane setup in Type IIB string theory [22,35,31]. Unlike the cases studied in [31,32], the N = (0, 4) configurations discussed in this paper involve 3d N = 4 gauge theories with Neumann boundary condition N or/and 2d N = (0, 4) gauge theories. 3 Accordingly, as we argue in the main text, they need more careful treatment in the computation of supersymmetric indices.…”