Learn in the textbookSets and Logical Operations
DefinitionOR (logical sum, 論理和) is an operation whose output is 1 if any one input is 1.
ExplanationThe output is 0 only when every input is 0, and in set terms it corresponds to the union, which gathers the elements in either set. It joins conditions with "or" to widen the range of targets.
AnalogyA home arrival chime that rings whether you come in through the front door or the back door.
Memory hookIt is sometimes written ∨ or "+", and the only difference from ordinary addition is that 1 + 1 is also treated as 1.