Question

the symbol of null set

Answer 1

The latter two symbols were introduced by the Bourbaki group (specifically André Weil) in 1939,inspired by the letter Ø in the Norwegian and Danish alphabets (and not related in any way to the Greek letter Φ). In linguistics, the null sign is used to indicate the absence of an element, such as a sound or morpheme.

Answer 2

The symbol of null set is { } or ∅ .