Search results
Results from the WOW.Com Content Network
In logic, the symbol ⊨, ⊧ or is called the double turnstile.It is often read as "entails", "models", "is a semantic consequence of" or "is stronger than". [1]It is closely related to the turnstile symbol , which has a single bar across the middle, and which denotes syntactic consequence (in contrast to semantic).
(the symbol may also indicate the domain and codomain of a function; see table of mathematical symbols). ⊃ {\displaystyle \supset } may mean the same as ⇒ {\displaystyle \Rightarrow } (the symbol may also mean superset ).
The syntactic consequence of provability should be contrasted to semantic consequence, denoted by the double turnstile symbol . One says that S {\displaystyle S} is a semantic consequence of T {\displaystyle T} , or T ⊨ S {\displaystyle T\models S} , when all possible valuations in which T {\displaystyle T} is true, S {\displaystyle S} is ...
The turnstile symbol was originally introduced by Frege in 1879, but its current use only dates back to Rosser and Kleene (1934–1935). [9] Syntactic consequence does not depend on any interpretation of the formal system. [10]
The second is a link to the article that details that symbol, using its Unicode standard name or common alias. (Holding the mouse pointer on the hyperlink will pop up a summary of the symbol's function.); The third gives symbols listed elsewhere in the table that are similar to it in meaning or appearance, or that may be confused with it;
Symbols surround us, guiding us, protecting us and communicating important messages every day. From mathematical symbols to road signs, these icons play a crucial role in our lives, often ...
A symbol is an idea, abstraction or concept, tokens of which may be marks or a metalanguage of marks which form a particular pattern. Symbols of a formal language need not be symbols of anything. For instance there are logical constants which do not refer to any idea, but rather serve as a form of punctuation in the language (e.g. parentheses ...
Hazard symbols; List of mathematical constants (typically letters and compound symbols) Glossary of mathematical symbols; List of physical constants (typically letters and compound symbols) List of common physics notations (typically letters used as variable names in equations) Rod of Asclepius / Caduceus as a symbol of medicine