Abstract :
Let L be any one of W(n, 1), S(n, 1) H(n, 1), and K(n, 1) over an algebraically closed held F of characteristic p > 3. In this paper, we extend the results concerning modular representations of classical Lie algebras and semisimple groups to the case of L and obtain some properties of principal indecomposable modules of u(L) which parallel closely those of classical Lie algebras.