  Recently Alberto Elduque listed all simple and graded modulo 2 finite
dimensional Lie algebras and superalgebras whose odd component is the spinor
representation of the orthogonal Lie algebra equal to the even component, and
discovered one exceptional such Lie superalgebra in characteristic 5. For this
Lie superalgebra all inequivalent Cartan matrices (in other words, inequivalent
systems of simple roots) are listed together with defining relations between
analogs of its Chevalley generators.
