# hs35.mod	QLR2-MN-3-4
# Original AMPL coding by Elena Bobrovnikova (summer 1996 at Bell Labs).

# Ref.: W. Hock and K. Schittkowski, Test Examples for Nonlinear Programming
# Codes.  Lecture Notes in Economics and Mathematical Systems, v. 187,
# Springer-Verlag, New York, 1981, p. 58.

# Number of variables:  3
# Number of constraints:  4
# Objective nonseparable convex quadratic
# Linear constraints


var x{1..3} >= 0;

minimize f:
       9 - 8*x[1] - 6*x[2] - 4*x[3] + 2*x[1]*x[1] + 2*x[2]*x[2]
       + x[3]*x[3] + 2*x[1]*x[2] + 2*x[1]*x[3];

s.t. Constr:
     3 >= x[1] + x[2] + 2*x[3];

data;

var x :=
    1   .5
    2   .5
    3   .5;

solve;

display f;