## Archive for February, 2010

### zine fodder

Symbols Used

$\Bbb N$ the set of natural numbers, “en”

$\Bbb Z$ the set of integers, “zee”

$\Bbb Z^+$ the positive integers, “zee-plus”

$\in$ “is an element of”; e.g. $-3\in \Bbb Z$, $-3\not\in \Bbb N$

# the number of elements for a (finite) set.
# (more generally) the “cardinality” of a set (finite or not)

$X \cup Y$ the union of (sets) X and Y
$X \cup Y$ the collection (set) of objects belonging X alone, or to Y alone, or to both.

W := C the symbol “W” stands for the code “C”
W := C “W equals C by definition

{…} the set containing “…” (typically a list of “elements”)

$\{P(x)\}_{x\in S}$ the collection of all (objects) “x”, taken from the set “S”, such that the proposition “P(x)” is true

$S^{\rightarrow}$ ess-arrow
$S^{\rightarrow}$ the “successor” of S

$\infty$ is well-known;
i’m lazy to look up aleph-null.

*********************************************************
the set of natural numbers, “en”
the set of integers, “zee”
the positive integers, “zee-plus”
“is an element of”; e.g. ,
# the number of elements for a (finite) set. # (more generally) the “cardinality” of a set (finite or not)
the union of (sets) X and Y;
the collection (set) of objects belonging
to X alone, or to Y alone, or to both.
W := C the symbol “W” stands for the code “C”
(“W equals C by definition“)
{…} the set containing “…” (typically a list of “elements”)
the collection of all (objects) “x”,
taken from the set “S”, such that
the proposition “P(x)” is true
the “successor” of S (“ess-arrow”)
is well-known; i’m lazy to look up aleph-null.

munging code is fun and easy.

• ## (Partial) Contents Page

Vlorbik On Math Ed ('07—'09)
(a good place to start!)