Mathematical symbols dictionary

–  identically equal,

–  approximately equal,

~  –  approximately,

0.(12345)  –  the repeating decimal with the period 12345,

N – the set of natural numbers,

Z –  the set of whole numbers (integers),

R –  the set of real numbers,

–  an empty set,

–  an infinity sign,

–  an element x belongs to a set X ,

–  an element x doesn't belong to a set X ,

X Y –  a set X is a subset of a set Y ,

–  a union of sets X and Y ,

–  an intersection of sets X and Y ,

X \ Y –  a symmetric difference of sets X and Y ,

{ u n } –  a sequence with a general term u n ,

[ a , b ]  –  a numerical segment,

–  numerical semi-segments (semi-intervals),

( a , b )  –  a numerical interval,

–  a scalar product of vectors ,

–  a vector product of vectors ,

==>   –  it follows,

<=>   –  equivalent,

–  perpendicular,

–  parallel,

–  a triangle ABC,

–  a function and its derivative.