@MartinSleziak The OP has edited the tags on that question and replaced topological-dynamics with dynamical-systems.

It seems that this was the first occurrence of a tag with this name (barring the possibility that such tag might have been merged by a mod or removed by the "single occurrence in 6 months" script).

SEDE: data.stackexchange.com/math/query/927958/… data.stackexchange.com/math/query/883845/… data.stackexchange.com/math/revision/1038474/1282557/…