\ Model qjh_uncon
\ Optimal solution [1, 5, 2] with objective value -5.5
Minimize
  - x2 - 3 x3 + [ 2 x1 ^2 - 2 x1 * x3 + 0.2 x2 ^2 + 2 x3 ^2 ] / 2 
Subject To
Bounds
 x1 free
 x2 free
 x3 free
End