证明
Definition 50 ([Available generator]). On the cross edge (i,j) , an available…Proposition 49 ([The limiting overlap obstruction]). Assume. In the common…观点
Apply finite-dimensional duality to the linear constraint map on _ i,j V_ ij . The coefficients of the four coupled equations are s_j,r_i , giving separately on each edge. If they were all zero, the local projection onto (q,h_ A,i +h_ B,j , x_ A,i , x_ B,j ) would be surjective by, forcing all other dual coefficients to vanish. Hence a nonzero obstruction uses some coupled equation. Conversely the constraint target lies in the image exactly when it annihilates every dual relation. The coupled targets are zero, so their evaluated contribution is the sum stated in the lemma.