Complex sentence: In mathematics, the Lagrangian Grassmannian is the smooth manifold of Lagrangian subspaces of a real symplectic vector space "V" whose dimension is "n (n +1)/2" (where the dimension of "V" is "2n").
Split into simpler sentences: In mathematics, the Lagrangian Grassmannian is the smooth manifold of Lagrangian subspaces of a real symplectic vector space "V". Its dimension is "n (n +1)/2" (where the dimension of "V" is "2n").