Extensions of simple modules for the group Sp(4,K). II (Q752849)

This paper is a continuation of part I [J. Lond. Math. Soc., II. Ser. 41, 51-62 (1990; Zbl 0715.20026)]. Because \(Ext^ 1_{{\mathcal G}_ 1}(L(\lambda),L(\lambda))\) may be not equal to 0 for some \(\lambda\in {\mathcal X}_ 1(T)\) when \(p=2\), it makes the task more complicated in this case. In the present paper we determine \(Ext^ 1_{{\mathcal G}}\) when \(p=2\).