ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  cneg Structured version   GIF version

Syntax Definition cneg 6940
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 6939 () to prevent syntax ambiguity. For example, looking at the syntax definition co 5455, 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.
Hypothesis
Ref Expression
cA class A
Assertion
Ref Expression
cneg class -A

See definition df-neg 6942 for more information.

Colors of variables: wff set class
  Copyright terms: Public domain W3C validator