On mixed vs. exclusively-bosonic $$\left\{ {\left[ {\tilde \lambda } \right]:p \leqslant 2^2 } \right\}$$ (SU2�S n ) irrep sets over $$\left\{ \tilde {\mathbb{H}}_v \right\}$$ carrier subspaces, in the structure of (SU2 �S n ?(SU2�S n )?)-derived Liouville space of NMR spin dynamics