> You shouldn't imply that oligopoly is not a form of monopoly.

But the article said 'monopoly', not 'oligopoly'.

Monopoly is a form of oligopoly. But oligopoly is not a form of monopoly.

All monopolies are oligopolies. Not all oligopolies are monopolies.

This chicken situation is maybe an oligopoly. It isn't a monopoly.

If you think a situation with multiple supplies and limited competition is a monopoly, then I'd ask you... why do we also have the term oligopoly? What do you think the difference is?