function g = checkmu(K,phi0,mu,m,n)
[Ainf,Binf] = lipab(m,n-1);
phi = phi0 - mu;
phi1 = getK1(K.*phi',m,n);

%cphi1 = (phi1-min(phi1));
%cphi1 = (phi1-min(phi1));
d = max(abs(Ainf*phi1));
cphi1 = phi1/d;
%cphi1 = cphi1 - min(cphi1);
%cphi1 = ceil(cphi1);

% check lip:
islip = all(Ainf*(cphi1)<=Binf+1e-8);

phi1 = phi1';
cphi1 = cphi1';

% check bound
K1 = getK1(K,m,n);
s1 = phi1*K1;
s2 = cphi1*K1;
bd = 1e-9 + abs(s2) - abs(s1) > 0;
%bd = (cphi1-phi1)*K1 + 1e-9 > 0;

g = (islip & bd);

return