New posts in examples-counterexamples

non time constructible functions [duplicate]

Is there a counterexample to this weakened converse of Hall's theorem?

Is there a simple geometric example of unequal left and right cosets?

The "true" domain of random variables

Proving the derived set $E'$ is closed.

Examples of a quotient map not closed and quotient space not Hausdorff

The perception of mathematics

Is this kind of space metrizable?

Integral extensions of rings, when one of the rings is a field

If a sub-C*-algebra does not contain the unit, is it contained in a proper ideal?

K topology: Examples

Examples of non-Euclidean domains which have a universal side divisor

Examples of provably${}^n$ unprovable statements

Some examples in C* algebras and Banach * algebras

Example of a set $Y$ that has zero Lebesgue measure and a continuous function $f$ such that $f(Y)$ is not a set of zero Lebesgue measure.

Lifting a convergent net through a quotient map

How does the method of Lagrange multipliers fail (in classical field theories with local constraints)?

Are elements commutative when subgroups are?

Can the long line be embedded in euclidean space?

The topology on $X/{\sim}\times X/{\sim}$ is not induced by $\pi\times\pi$.