Automorphisms of the Lie algebra of upper triangular matrices over a connected commutative ring (Q1340003)

Let \(R\) be a nontrivial commutative ring, \(t\) the Lie algebra over \(R\) consisting of all upper triangular \(n \times n\)-matrices over \(R\). The automorphism group of \(t\) viewed as an associative \(R\)-algebra has been determined by \textit{T. P. Kezlan} [Linear Algebra Appl. 135, 181-184 (1990; Zbl 0706.15016)]. In this article the author describes the automorphism group of the Lie algebra \(t\) for the case when \(R\) has no idempotents except 0 and 1.