Learn in the textbookSets and Logical Operations
DefinitionNOT (negation, 否定) is an operation that swaps 0 and 1 for a single input.
ExplanationIt is a unary operation that takes a single input, unlike operations that combine two inputs. In set terms it corresponds to the elements not in a set, that is, the complement, and in a Venn diagram it is the region outside a circle.
AnalogyA button that switches between on and off each time you press it.
Memory hookApplying NOT twice in a row gives back the original value (the negation of a negation is an affirmation).