Use AddMaxEquality to find the max sum of bools

Question

How can one use AddMinEquality and AddMaxEquality to distribute assignments evenly? My model variables are boolean, hence I try to minimize difference between maximum and minimum of sum of bools.

assignments = []
for c in cars:
    a = model.NewIntVar(0, total_assignments, c)
    model.Add(a == sum(car_sch[(d, c)] for d in days))
    assignments.append(a)

assignment_min = model.AddMinEquality(assignments)  
assignment_max = model.AddMaxEquality(assignments)

model.Minimize(assignment_max - assignment_min)

Answer 1

After some testing

assignments = []
for c in cars:
    a = model.NewIntVar(0, total_assignments, c)
    model.Add(a == sum(car_sch[(d, c)] for d in days))
    assignments.append(a)

min_value = model.NewIntVar(0, total_assignments, "min val") 
assignment_min = model.AddMinEquality(assignments) 
max_value = model.NewIntVar(0, total_assignments, "max val") 
assignment_max = model.AddMaxEquality(assignments)

model.Minimize(max_value - min_value)