Lie algebras MOC Quadratic Lie algebra A quadratic Lie algebra over π consists of a Lie algebra π€ over π with a π€-invariant symmetric linear form β¨ β , β β© :π€ Γπ€ βπ,1 lie i.e. it is both a Lie algebra and a Quadratic space in a compatible way, namely β¨[π₯,π¦],π§β©=β¨π₯,[π¦,π§]β© See also Category of quadratic Lie algebras tidy | en | SemBr Footnotes Away from 2 β©