Epsilon neighbourhood of a point. An open set.

[@jakehenri9608]

Thank you for the video. I thought the speed was perfect at 1.

[@anechkaegoshina3445]

Все чётко, доступно, понятно. Спасибо)

[@obelusstem199]

лол

[@08Billmr]

Do you have any source, where we can read more about? Thank you!