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.

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