function gamsrobot1

x1 = sdpvar(1,1);
x2 = sdpvar(1,1);
x3 = sdpvar(1,1);
x4 = sdpvar(1,1);
t = sdpvar(1,1);
p = x1 - x2 - x3 - x1*x3 + x1*x4 + x2*x3 - x2*x4;
F = set(x1+4*x2 <= 8) + set(4*x1+x2 <= 12) + set(3*x1+4*x2 <= 12) + set(2*x3+x4 <= 8) + set(x3+2*x4 <= 8) + set(x3+x4 <= 5)+set([x1;x2;x3;x4]>0);
F = F+set(p<t);
obj = t;

sol = solvesdp(F,obj,sdpsettings('solver','bmibnb'))

mbg_asserttolequal(sol.problem,0);
mbg_asserttolequal(double(obj),-13, 1e-8);