Furthermore, if F(x) is B -differentiable at a solution x * of F(x) =0 and BF(x* ) is symmetric nonsingular (BF(x* ) is symmetric positive definite for DFP method), q-superlinear convergence is proven for PSB and DFP methods.

• 若更进一步假设F(x)在解x~*处是B可微的(即BF(x~*)存在),且BF(x~*)对称非奇异(对DFP方法还需假设BF(x~*)正定),还证明了PSB方法及DFP方法的q~-超线性收敛性。