At tracing abstract signature, I looks like odd ordering

[cutsea110]

My code looks like below.

open util/ordering[Student]

enum Type { X, Y }

abstract sig Student{
        T : Type,
        TransHistory: set TransRecord
}
sig StudentX extends Student{
}{
        T = X
}
sig StudentY extends Student{
}{
        T = Y
}

sig TransRecord{
}

pred init(s: Student){
        no s.TransHistory
}

fact traces{
        first.init
        all s: Student - last | let s' = s.next |
                some x: TransRecord |
                        s'.TransHistory = s.TransHistory + x and s'.T = s.T
}

run {} for 5

I projected about Student and executed tracing, it was traced as 0 -> 1 -> 2 ... However, when checked in the evaluation environment, it is as follows.

Student<:first => StudentX$2
Student<:first.next => StudentX$4
Student<:first.next.next => StudentX$0
Student<:first.next.next.next => StudentX$3
Student<:first.next.next.next.next => StudentX$1

In other words, it became random internally and it seemed that the meaning did not go through as trace.

I understand the reason. It is because it orders Student and it is not attached to StudentX. But, then, I think that I want the execution trace to be displayed in order of the student being ordered, and I think that is more reasonable.