New posts in definition

Is any necessary and sufficient criteria for a topological space to be compact using continuous functions?

Question regarding baby do Carmo's definition of a regular surface.

Measure and metric

Differentiable at a point

Definition of Network Units: Fragment, Segment, Packet, Frame, Datagram

What is the meaning and reasoning behind the Open/Closed Principle?

Theory of definitions

$0^0$ is undefined, but sometimes defined as $1$?

In which topologies do open sets maintain open under countable or arbitrary intersection?

What is the constant function, exactly?

Question about basis and finite dimensional vector space

Support of a distribution, what does it mean?

Domain of an operator in functional analysis

What is the "Principle of permanence"?

Why is the matrix multiplication defined as it is? [duplicate]

How is "point" in geometry undefined? And What is a "mathematical definition"? [duplicate]

Symmetric property of a binary relation

Is the free group on an empty set defined?

Why can't $|x-2|$ be less than zero?

If sum of triangle angles is $180$ degrees, how $\sin(270)$ is possible?