\xymatrix{
	\cdots \ar[r] & \pi_{i+1}(B_f, A) \ar[r] \ar[d] & \pi_i(A) \ar[r]^{f_\ast} \ar[d] & \pi_i(B) \ar[r] \ar[d] & \pi_i(B_f, A) \ar[r] \ar[d] & \cdots \\
	\cdots \ar[r] & H_{i+1}(B_f, A) \ar[r] & H_i(A) \ar[r]^{f_\ast} & H_i(B) \ar[r] & H_i(B_f, A) \ar[r] & \cdots \\
}
