Your comment led me down a bit of a rabbit hole and I found this on Wikipedia:
When writing in languages such as Danish and Norwegian, where the empty set character may be confused with the alphabetic letter Ø (as when using the symbol in linguistics), the Unicode character U+29B0 ⦰ REVERSED EMPTY SET may be used instead.
It also mentions what you are alluding to:
In the past, “0” (the numeral zero) was occasionally used as a symbol for the empty set, but this is now considered to be an improper use of notation.
And, as a programmer, don’t get me started on nulls…or undefined…or truthyness.
As a former math major, it annoys me because 0 and Ø are different concepts.
Your comment led me down a bit of a rabbit hole and I found this on Wikipedia:
It also mentions what you are alluding to:
And, as a programmer, don’t get me started on nulls…or undefined…or truthyness.
Wait, what.
… oh no. Nope.
Nope, not going back to set theory, it is 105F / ~40C right now, highly confident I would give myself heat stroke.