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Syntax Definition cneg 7957
Description: Extend class notation to include unary minus. The symbol - is not a class by itself but part of a compound class definition. We do this rather than making it a formal function since it is so commonly used. Note: We use different symbols for unary minus (-) and subtraction cmin 7956 () to prevent syntax ambiguity. For example, looking at the syntax definition co 5781, if we used the same symbol then "( − 𝐴𝐵) " could mean either "𝐴 " minus "𝐵", or it could represent the (meaningless) operation of classes " " and "𝐵 " connected with "operation" "𝐴". On the other hand, "(-𝐴𝐵) " is unambiguous.
Ref Expression
cA class 𝐴
Ref Expression
cneg class -𝐴

See definition df-neg 7959 for more information.

Colors of variables: wff set class
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