--- format: markdown toc: yes title: Mathematical Proof Study Notes ... # Texts - *Book of Proof*, Richard Hammack # Reading Notes ## *Hammack*, 25 Jan 2014 All of Mathematics can be described with *sets*. *set* : A collection of things. The things in the set are called *elements*. An example of a set: $\{2,4,6,8\}$ The set of all integers: $$ \{\dots, -4, -3, -2, -1, 0, 1, 2, 3, 4, \dots\} $$ The dots mean the expressed pattern continues. Sets of infinitely many members are *infinite*, otherwise they are *finite*. Sets are *equal* if they have exactly the same elements. E.g. $\{2,4,5,8\} = \{4,2,8,6\}$ but $\{2,4,6,8\} \neq \{2,4,6,7\}$. Uppercase letters often denote sets, e.g. $A = \{1,2,3,4\}$. To express membership, we use $\in$, as in $2 \in A$.