Can someone help solve this Error? Thank you.

Here is the function:

function [L,U] = eluinv(A)

[~,n]=size(A);

[L,U] = lu(A);

format compact

if closetozeroroundoff(A,7) == closetozeroroundoff(L*U,7)

disp('Yes, I have got LU factorization')

end

if closetozeroroundoff(rref(U),7) == closetozeroroundoff(rref(A),7)

disp('U is an echelon form of A')

else

disp('Something is wrong')

end

if rank(A) ~= min(size(A))

sprintf('A is not invertible')

invA=[];

return

else

leye = [L eye(size(L,1))];

ueye = [U eye(size(U,1))];

invLech = rref(leye);

invUech = rref(ueye);

invL = invLech(:,(n+1):size(invLech,2));

invU = invUech(:,(n+1):size(invUech,2));

invA = invU*invL;

if isequal(closetozeroroundoff(invA-inv(A),7),zeros(size(A)))

disp('Yes, LU factorization works for calculating the inverses')

else

disp('LU factorization does not work for me?!')

end

end