(from Jantzen: Quantum Groups)
(R2) means:
- the q(α,β)-commutator
of Kα and Eβ vanishes...
Similarly (R3)
(R4) identifies
-
the commutator of Eα and
Fβ
with an element in the subalgebra generated by the K's.
The relations (R5) and (R6) are called quantized Serre relations.