BASBLib - A Library of Bilevel Test Problems

A growing collection of bilevel problems

Nonlinear-Nonlinear bilevel problem from (Colson, 2002)


Optimal solution

Objective values Solution point
F* = 227.691 x* = 6.082
f* = 0.000 y* = 4.487

Sources where this problem occurs

Original source:

Other sources:

Description of the problem in the AMPL format

var x >= 0, <= 15;         # Outer variable
var y >= 0, <= 20;         # Inner variable
var l{1..3} >= 0, <= 100;  # KKT Multipliers

minimize outer_obj: (10 - x)^3 + (10 - y)^3;  # Outer objective

subject to
# Outer constraints
    outer_con:  -x + y <= 0;
# Inner objective:
    inner_obj: (x + 2*y - 15)^4 = 0;
# Inner constraints
    inner_con:   x + y - 20 <= 0;
# KKT conditions:
    stationarity:      8*(x + 2*y - 15)^3 + l[1] - l[2] + l[3] = 0;
    complementarity_1: l[1]*(x + y - 20) = 0;
    complementarity_2: l[2]*y = 0;
    complementarity_3: l[3]*(y - 20) = 0;

References