This kind of symbol is used to denote morphisms that are treated as their own objects, the slice category.
This kind of symbol is used to denote morphisms that are treated as their own objects, the slice category. Though it is not a pipe or dagger, the Sheffer stroke is sometimes denoted using a form of this symbol named for Charles Sanders Peirce; that symbol is sometimes called the "Quine dagger" and is used to represent the NAND operation. In another notation that uses these symbols, removing them creates power towers, allowing for the hyperoperation of exponentials. These symbols are used to express incredibly large numbers in a notation developed by Donald Knuth. To convey the meaning of "iff", spelled "I-F-F", a double-headed one of these symbols is used. For 10 points, name this symbol used to signify conditionals, such as p implies q.
This kind of symbol is used to denote morphisms that are treated as their own objects, the slice category.
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