Notation in Math 185 Dave Penneys
Here is some notation we have seen thus far.
Cmeans the set of complex numbers.
Rmeans the set of real numbers.
Qmeans the set of rational numbers.
Zmeans the set of integers.
Nmeans the set of natural numbers.
X⊂Ymeans that the set Xis a subset of Y. This means the set Xis contained in the set
Y. For example,
N⊂Z⊂Q⊂R⊂C.
f:X→Ymeans fis a function from the set Xto the set Y.
x7→ ymeans the element xmaps to the element y.
x∈Xmeans that xis an element of X.
X×Yis the cartesian product of Xand Y. It is the set of all ordered pairs (x, y ) such that
x∈Xand y∈Y.
X×Y=(x, y)
x∈Xand y∈Y.
∀means “for all.”
∃means “there exists.”
s.t. means “such that.”
! means “unique” (or factorial if after a number).
=⇒means “implies.”
¬is the Boolean symbol for “not.”
∧is the Boolean symbol for “and.”
∨is the Boolean symbol for “or.”
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