text: #  NLP written by GAMS Convert at 04/21/18 13:54:25
  #  
  #  Equation counts
  #      Total        E        G        L        N        X        C        B
  #          6        1        0        5        0        0        0        0
  #  
  #  Variable counts
  #                   x        b        i      s1s      s2s       sc       si
  #      Total     cont   binary  integer     sos1     sos2    scont     sint
  #          3        3        0        0        0        0        0        0
  #  FX      0        0        0        0        0        0        0        0
  #  
  #  Nonzero counts
  #      Total    const       NL      DLL
  #         13       11        2        0
  # 
  #  Reformulation has removed 1 variable and 1 equation
  
  
  from pyomo.environ import *
  
  model = m = ConcreteModel()
  
  
  m.x1 = Var(within=Reals,bounds=(0,None),initialize=0)
  m.x2 = Var(within=Reals,bounds=(0,None),initialize=0)
  
  m.obj = Objective(expr=(-m.x1**2) - 4*m.x2**2, sense=minimize)
  
  m.c1 = Constraint(expr=   m.x1 + m.x2 <= 10)
  
  m.c2 = Constraint(expr=   m.x1 + 5*m.x2 <= 22)
  
  m.c3 = Constraint(expr= - 3*m.x1 + 2*m.x2 <= 2)
  
  m.c4 = Constraint(expr= - m.x1 - 4*m.x2 <= -4)
  
  m.c5 = Constraint(expr=   m.x1 - 2*m.x2 <= 4)
  