Proving that the non-negative real line is complete
13848
Showing that if a subset of a complete metric space is closed, it is also complete
152921
Proving that Unit Intersection is NP-complete
101712
Let $X$ be obtained by removing finitely many lines from $\mathbb{R}^3$. How do I prove $X$ is connected?
93342
Show that $\neg$ and $\wedge$ form a functionally complete collection of logical operators.
776
Entire function with positive real part is constant (no Picard)
102307
Discrete Math Proofs Involving Real Numbers
158569
Proving a particular subset of $R^n$ is closed
139176
The real line is not homeomorphic to any non-trivial product space
132641
Proving that Euclidean Space is a complete metric space
120065
Niven’s theorem proof.
115272
Showing that projections $\mathbb{R}^2 \to \mathbb{R}$ are not closed
22232
Proving that cardinality of the reals = cardinality of $[0,1]$
76482
Closure of the set of degree $n$ polynomials with $n$ real roots
9146
Proving that a list of perfect square numbers is complete
44912
Prove that $ \overline {A^\complement} = (A°)^\complement $
131000
A proof of a criterion of vanishing of a function.
73807
Prove positive definiteness