Set Inequality

From ProofWiki
Jump to: navigation, search

Theorem

$S \ne T \iff \left({S \nsubseteq T}\right) \lor \left({T \nsubseteq S}\right)$


Proof

\(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\displaystyle S \ne T\) \(\iff\) \(\displaystyle \neg \left({S = T}\right)\) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \)                    
\(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\iff\) \(\displaystyle \neg \left({\left({S \subseteq T}\right) \land \left({T \subseteq S}\right)}\right)\) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \)          Equality of Sets          
\(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\iff\) \(\displaystyle \neg \left({S \subseteq T}\right) \lor \neg \left({T \subseteq S}\right)\) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \)          De Morgan's Laws          
\(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \) \(\iff\) \(\displaystyle \left({S \nsubseteq T}\right) \lor \left({T \nsubseteq S}\right)\) \(\displaystyle \) \(\displaystyle \) \(\displaystyle \)                    

$\blacksquare$

Personal tools
Namespaces
Variants
Actions
Navigation
ProofWiki.org
ToDo
Toolbox
Google AdSense