Caret confused with other chevron-shaped characters, such as or , which may occasionally be called carets, too. The caret was originally and continues to be used in handwritten form as a proofreading mark to indicate where a punctuation mark, word, or phrase should be inserted into a document. The term comes from the Latin , "it lacks", from , "to lack; to be separated from; to be free from". The caret symbol is written below the line of text for a line-level punctuation mark, such as a comma, or above the line as an inverted caret (cf. ) for a higher
Wolfram's 2-state 3-symbol Turing machine universal, though the proof was initially disputed. The following table indicates the actions to be performed by the Turing machine depending on whether its current state is A or B, and the symbol currently being read is 0, 1 or 2. The table entries indicate the symbol to be printed, the direction in which the tape head is to move, and the subsequent state of the machine. The (2,3) Turing machine: Minsky (1967) briefly argued that standard (2,2) machines cannot be universal and M. Margenstern (2010) provided a mathematical proof based on a result by L. Pavlotskaya in 1973 (not