SetSubtractIntervalAndInterval​(AngouriMath.​Entity.​Set.​Interval,​AngouriMath.​Entity.​Set.​Interval)

Each part ends where B begins, and holds that end where
B does not: [0; 10] \ (2; 3) is [0; 2] \/ [3; 10],
and [0; 10] \ (0; 3) is { 0 } \/ [3; 10]. One interval from an end of
A to the far end of B was answered for the first,
[0; 3], the end of the cut was read from the other end of
B, and an end of A that B left
was lost. The ends are compared by their values, as the intersection compares them,
and kept as written. Where an end has no value the difference is left as it is, unless
the ends are the same and B holds every end A holds; then it holds all of A. Where A holds an
end that B does not, what is left depends on the order of the ends:
[a; b] \ (a; b) is { a, b } where a < b and nothing where
a > b.
https://github.com/asc-community/AngouriMath/issues/2290