Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Logical connective
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Order of precedence== As a way of reducing the number of necessary parentheses, one may introduce [[precedence rule]]s: ¬ has higher precedence than ∧, ∧ higher than ∨, and ∨ higher than β. So for example, <math>P \vee Q \and{\neg R} \rightarrow S</math> is short for <math>(P \vee (Q \and (\neg R))) \rightarrow S</math>. Here is a table that shows a commonly used precedence of logical operators.<ref>{{cite book|title=Discrete Mathematics Using a Computer|first1=John|last1=O'Donnell|first2=Cordelia|last2=Hall|first3=Rex|last3=Page| publisher=Springer| year=2007| isbn=9781846285981|page=120|url=https://books.google.com/books?id=KKxyQQWQam4C&pg=PA120}}.</ref><ref name=":35">{{Cite book |last1=Allen |first1=Colin |title=Logic primer |last2=Hand |first2=Michael |date=2022 |publisher=The MIT Press |isbn=978-0-262-54364-4 |edition=3rd |location=Cambridge, Massachusetts}}</ref> {| class="wikitable" style="text-align: center;" !Operator !!Precedence |- | <math>\neg</math> || 1 |- | <math>\and</math> || 2 |- | <math>\vee</math> || 3 |- | <math>\rightarrow</math> || 4 |- | <math>\leftrightarrow</math> || 5 |} However, not all compilers use the same order; for instance, an ordering in which disjunction is lower precedence than implication or bi-implication has also been used.<ref>{{cite book|title=Software Abstractions: Logic, Language, and Analysis | first=Daniel|last=Jackson|publisher=MIT Press|year=2012|isbn=9780262017152|page=263| url=https://books.google.com/books?id=DDv8Ie_jBUQC&pg=PA263}}.</ref> Sometimes precedence between conjunction and disjunction is unspecified requiring to provide it explicitly in given formula with parentheses. The order of precedence determines which connective is the "main connective" when interpreting a non-atomic formula.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)