ABSTRACT
In1893,J.Hadamardpublishedhiscelebratedtheoremondeterminants(Theorem2.41):IfA~0,then
h(A)~det(A), where,recall,h(A)istheproductofthemaindiagonalentriesofA.SupposeA~0 ispartitionedintoblocks,
whereAnandA22aresquare.ItfollowsfromHadamard'sTheoremthat
h(A)~det(Au)det(A22),A~0.
