Branching rules for quantum toroidal glngln

We construct an analog of the subalgebra Ugl(n)⊗Ugl(m)⊂Ugl(m+n)Ugl(n)⊗Ugl(m)⊂Ugl(m+n) in the setting of quantum toroidal algebras and study the restrictions of various representations to this subalgebra.