≠
Not equal to
≈
Approximately equal to
≡
Means two things are equal
P ==> q
( e.g. if it's raining in p , then it's pouring in q)
P <==> q
(P implies q and q implies p)
Z
The set of integers (positive or nagative haumbors -1,0,1)
N
The set of natural numbers (only fosibive numbers 0,1,2,3)
Q
The set of rational number (can be writen as afraction)
R
The set of real numbers (all humber even the decimal numbers)
∈
X∈Z
It is a member of
X is in the set of integers
Zuletzt geändertvor einem Jahr