local kiwi = require("kiwi")

local Var = kiwi.Var

x1 = Var("x1")
x2 = Var("x2")
xm = Var("xm")

local constraints = { x1:ge(0), x2:le(100), x2:ge(x1 + 10), xm:eq((x1 + x2) / 2) }

local solver = kiwi.Solver()

for _, c in ipairs(constraints) do
   solver:add_constraint(c)
end

local c = kiwi.constraints.single(x1, 40, "EQ", kiwi.Strength.WEAK)
solver:add_constraint(c)

constraints[#constraints + 1] = c

solver:add_edit_var(xm, kiwi.Strength.STRONG)

solver:suggest_value(xm, 60)

solver:update_vars()

print(xm:value(), x1:value(), x2:value())

for _, c in ipairs(constraints) do
   print(c, c:violated())
end

solver:suggest_value(xm, 90)
solver:update_vars()

print(xm:value(), x1:value(), x2:value())

for _, c in ipairs(constraints) do
   print(c, c:violated())
end