  We give new combinatorial formulas for decomposition of the tensor product of
integrable highest weight modules over the classical Lie algebras of type $B,
C, D$, and the branching decomposition of an integrable highest weight module
with respect to a maximal Levi subalgebra of type $A$. This formula is based on
a combinatorial model of classical crystals called spinor model. We show that
our formulas extend in a bijective way various stable branching rules for
classical groups to arbitrary highest weights, including the Littlewood
restriction rules.
