Horseshoe
[ Whitehead, A.N., and Russell, Bertrand, '' Principia Mathematica''] (⊃, \supset in TeX) is a
symbol
A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...
used to represent:
*
Material conditional in
propositional logic
*
Superset in
set theory
Set theory is the branch of mathematical logic that studies sets, which can be informally described as collections of objects. Although objects of any kind can be collected into a set, set theory, as a branch of mathematics, is mostly conce ...
It was used by
Whitehead and
Russell
Russell may refer to:
People
* Russell (given name)
* Russell (surname)
* Lady Russell (disambiguation)
* Lord Russell (disambiguation)
Places Australia
*Russell, Australian Capital Territory
*Russell Island, Queensland (disambiguation)
**Ru ...
in ''
Principia Mathematica''. In Unicode the symbol is encoded .
See also
*
List of mathematical symbols
*
List of logic symbols
*
⊂
*
ÊŠ
*
Ω
References
{{Common logical symbols
Logic symbols