In the same paper, Peirce introduces a symbol for the logically dual operator. This was rendered by the editors of his ''Collected Papers'' as an inverted Aries symbol with a bar or a serif at the top, in this way denoting the connective or logical operator that is currently called the ''[[alternative denial]]'' in logic, the NAND operator in computer science, or invoked by means of phrases like "not-and" or "not both" in ordinary language. It is not clear whether it was Peirce himself or later writers who initiated the practice, but on account of their dual relationship it became common to refer to these two operators in the plural, as the ''amphecks''. | In the same paper, Peirce introduces a symbol for the logically dual operator. This was rendered by the editors of his ''Collected Papers'' as an inverted Aries symbol with a bar or a serif at the top, in this way denoting the connective or logical operator that is currently called the ''[[alternative denial]]'' in logic, the NAND operator in computer science, or invoked by means of phrases like "not-and" or "not both" in ordinary language. It is not clear whether it was Peirce himself or later writers who initiated the practice, but on account of their dual relationship it became common to refer to these two operators in the plural, as the ''amphecks''. |