The error about pow_abs

Hello,everyone! I meet a problem about pow_pos(),my code and error are as follow. Do you know what causes it?

constant: r_ie(E,N), V(1,E), hmin_eu(E,N), sum_e(E,N), v(2,E), y_f(2,1), lamb=10;
variable: y(2,1)

My Code:

for e=1:E
    I3(e,:)=r_ie(e,:)-(V(e)./(hmin_eu(e)+sum_e(e,:))).*(pow_abs((norm(y(:)-v(:,e))+lamb),2)-(norm(y_f-v(:,e))+lamb).^2);
end

CXV Error:

错误使用 cvx/pow_cvx (line 144)
Disciplined convex programming error:
Illegal operation: pow_abs( {convex}, {2} )
Error: cvx/pow_abs (line 13)
y = pow_cvx( x, p, ‘pow_abs’ );

Thank you for your attention!
I have found the solution to the problem in CVX Forum.

Revised Code:

for e=1:E
I3(e,:)=r_ie(e,:)-(V(e)./(hmin_eu(e)+sum_e(e,:))).*(square_pos(norm(y-v(:,e))+lamb)-(norm(y_f-v(:,e))+lamb).^2);
end