#This is problem 4.1 from
#http://www.cs.cas.cz/ics/reports/v798-00.ps
# use NDA_MIN
#converted to AMPL by Yu-Ju Kuo and Hans D. Mittelmann
var x1 := 1;
var x2 := 2;
var f{1..3};
option substout 1;
s.t. f1def: f[1] = x1^2+x2^2+x1*x2-1;
s.t. f2def: f[2] = sin(x1);
s.t. f3def: f[3] = -cos(x1);
minimize obj{i in 1..3}: f[i];
s.t. c1: x1+x2-0.5>=0;