message: doc: formula miss
diff: @@ -83,7 +83,7 @@ Let us define a kernel function \f$K(p,q)\f$ which does a dot product between tw
  \begin{aligned}
  K(p,q) = \phi(p).\phi(q) &= \phi(p)^T \phi(q) \\
  &= (p_{1}^2,p_{2}^2,\sqrt{2} p_1 p_2).(q_{1}^2,q_{2}^2,\sqrt{2} q_1 q_2) \\
  - &= p_1 q_1 + p_2 q_2 + 2 p_1 q_1 p_2 q_2 \\
  + &= p_{1}^2 q_{1}^2 + p_{2}^2 q_{2}^2 + 2 p_1 q_1 p_2 q_2 \\
  &= (p_1 q_1 + p_2 q_2)^2 \\
  \phi(p).\phi(q) &= (p.q)^2
  \end{aligned}
  