cooperative principle
Also known as Grice's maxims, conversation typically is a cooperative endeavor. If I say something to you, you will understand it under the lens of the assumption that I am trying to make you understand.
Alice: “I need gas”
Bob: “There is a gas station around the corner.”
Alice assumes that Bob is trying to be helpful, and thus assumes that Bob is implying (to the best of his knowledge) that the gas station is open, that it has gas Alice can use, etc. etc.
