The simple F2//Cmax with forbidden tasks in first or last position: A problem more complex that it seems

While it seems natural to think that a single rule (like Johnson's one) can be applied, all intuitive rules can be refuted by counterexamples. Surprisingly, this F2//Cmax with this additive constraint appears to be more “complicated” than the initial problem, even if it stay linear. Once again, the F2//Cmax appears to be a peculiarity in a complex environment.