Answer:
To show that A has a supremum is given as,
Step-by-step explanation:
Because A is that the set of all letters from the dictionary starting with the letter 'a'. And as after set A, there'll be a group containing all the opposite words .. so there exists some x during a such every other letter during a comes before it. So it's none aside from a word starting with the letter b therefore the supremum of the set A is letter b.