This glossary is far from complete. We are constantly adding math terms. For instructions on adding new terms, please refer to Math Glossary Main Page
1. The sets [math]\lbrace7,3,11,2,5\rbrace\,[/math] and [math]\lbrace11,7,5,3,2\rbrace\,[/math] are equal since both consist of the five prime numbers [math]2,3,5,7\,[/math] and [math]11\,[/math]. the order in which numbers appear is irrelevant.
2. The sets [math]\lbrace\delta,\alpha,\alpha,\alpha,\omega,\omega,\xi\rbrace\,[/math] and [math]\lbrace\delta,\alpha,\omega,\xi\rbrace\,[/math] are equal even though, in the first set element [math]\alpha\,[/math] is listed three times and element [math]\omega\,[/math] is listed twice. Both sets contain the four elements [math]\alpha,\delta,\xi,\omega\,[/math] and no others.