What is the examole of equal set ?

Two sets are equal, if they have exactly the same elements. Example: {a, c, t} = {c, a, t} = {t, a, c}, but {a, c, t} ≠ {a, c, t, o, r}. Example: {x : x is a letter in the word “book”} = {b, o, k}, but {b, o, k} ≠ {b, o, t}.

Explanation: