Regions of Tight Monomials in Quantum Group of Type A_4
A_4型量子群中紧单项式的区域

The global crystal basis or canonical basis plays an important role in the theory of the quantum groups and their representations. Tight monomials are the simplest elements in the canonical basis. Based on Lusztig's work, the regions of tight monomials in quantized enveloping algebra of type A-4 should be determined in this paper.