Video_98: Sub-matrices of the Incidence Matrix and a property of it

In this video, we discuss sub-matrices of the incidence matrix of a graph and prove the following statement related to a property of sub-matrices of the incidence matrix.
Let (G) be the incidence matrix of a connected graph G with n vertices. An (n-1)x(n-1) sub-matrix of A(G) is non-singular if and only if the n-1 edges corresponding to the n-1 columns of this matrix constitutes a spanning tree in G.