#  ___________________________________________________________________________
#
#  Pyomo: Python Optimization Modeling Objects
#  Copyright 2017 National Technology and Engineering Solutions of Sandia, LLC
#  Under the terms of Contract DE-NA0003525 with National Technology and 
#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain 
#  rights in this software.
#  This software is distributed under the 3-clause BSD License.
#  ___________________________________________________________________________
#
# Author:  Gabe Hackebeil
# Purpose: For regression testing to ensure that the Pyomo
#          NL writer properly labels constraint ids in the "J"
#          section of the NL file when trivial constraints exist.
#          At the creation of this test, trivial constraints
#          (constraints with no variables) are being written to
#          the nl file as a feasibility check for the user.
#
#          This test model relies on the gjh_asl_json executable. It
#          will not solve if sent to a real optimizer.
#

from pyomo.environ import ConcreteModel, Var, Objective, Constraint, RangeSet
model = ConcreteModel()

n=3

model.x = Var([(k,i) for k in range(1,n+1) for i in range(k,n+1)])

def obj_rule(model):
	return model.x[n,n]
model.obj = Objective(rule=obj_rule)

def var_bnd_rule(model,i):
	return (-1.0, model.x[1,i], 1.0)
model.var_bnd = Constraint(RangeSet(1,n),rule=var_bnd_rule)

model.x[1,1] = 1.0
model.x[1,1].fixed = True