What is the meaning of "\varnothing =\left \{ u:u\\eq u \right \}"?

Question

What is the meaning of "
`\varnothing =\left \{ u:u\\eq u \right \}`"?

Answer 1

The expression “8 = {u : u# u}” defines the empty set, which is a set that contains no elements. The notation “u# u” means that u is not equal to u, which is always false and therefore no element satisfies the condition, resulting in an empty set.