# Domains
var x1 >= -100, <= 100;
var x2 >= -100, <= 100;
var x3 >= -100, <= 100;
var x4 >= -100, <= 100;

subject to

cons1 : x1^2 - 0.2*x1 + x2 - 0.09 = 0;
cons2 : x2^2 - 0.2*x2 + x3 - 0.09 = 0;
cons3 : x3^2 - 0.2*x3 + x4 - 0.09 = 0;
cons4 : x4^2 - 0.2*x4 + x1 - 0.09 = 0;

# 
# 
# , x1 + x4^2 - (1/5)*x4 - (9/100) = 0,
# x4^16 - (8/5)*x4^15 + (6/5)*x4^14 - (14/25)*x4^13 + (91/500)*x4^12 -
# (273/6250)*x4^11 + (1001/125000)*x4^10 - (143/125000)*x4^9 +
# (1287/10000000)*x4^8 - (143/12500000)*x4^7 + (1001/1250000000)*x4^6 -
# (273/6250000000)*x4^5 + (91/50000000000)*x4^4 - (7/125000000000)*x4^3 +
# (3/2500000000000)*x4^2 + (62499999999999/62500000000000)*x4 -
# (999999999999999/10000000000000000) = 0,
# x2 + x4^4 - (2/5)*x4^3 + (3/50)*x4^2 - (1/250)*x4 - (999/10000) = 0
# 


solve;
display x1, x2, x3, x4;