$A$ normal and $Spec(A)={0,1}$ but $A$ not projector?
56943
Normal operator with real spectrum is hermitian.
21152
Exactly half of the elements of $\mathcal{P}(A)$ are odd-sized
128673
Given $A : \mathcal{C} \rightarrow \mathcal{E}$, when does $\operatorname{colim} A = A(1)$?
56817
How do you get \mathbb{1} to work (characteristic function of a set)?
158842
What is wrong with this bijection from all naturals to reals between 0 and 1?
35569
Prove that $[0,1]$ isn't homeomorphic to $\mathbb{R}$
138944
Is $\mathbb Z[\sqrt{-3}]$ Euclidean under some other norm?
28906
What are the differences between $$, \[, align, equation and displaymath?
20135
Measure of  reals in $[0,1]$ which don't have $4$ in decimal expansion
110830
Frobenius norm is not induced
151910
Why is $K^{\ast n}$ contained in the norm group?
81240
Norm of an inverse operator: $\|T^{-1}\|=\|T\|^{-1}$?
158082
Is $\|A^n\|=\|A\|^n$ true for any normal operator in a Hilbert space?
158924
Example of composition of two normal field extensions which is not normal.
29474
Compactness of $\operatorname{Spec}(A)$
125161
Why is the Cartesian product of $A$ and $\varnothing$ empty?
63516
$C^1[0,1]$ is not complete with respect to sup norm