Can you check my proof that $H$ is characteristic?
15630
Normal subgroup of prime order is characteristic
98542
Prove that $H$ is a subgroup of an abelian group $G$
78873
How to show that the monomials are not a Schauder basis for $C[0,1]$
114811
Characteristic subgroups and automorphisms
17191
How to verify $H\otimes K \cong \bigoplus\limits_{i\in I}H$
5526
Prove that $ℤ[i]^*= \{1,-1,i,-i\}$
130455
If $H,K⊲G$ and $H∩K = \{1_G\}$, then all elements in $H$ commute with all elements in $K$
98765
Showing that $G/(H\cap K)\cong (G/H)\times (G/K)$
62879
Question about the proof of $GCH$ holds in $\mathbf L$
48291
Proof that $\mathrm{ker}(f^*) = \mathrm{im}(f)^{\perp} $
70776
Characteristic of a field is $0$ or prime
153480
Roots of a characteristic equation. Can Mathematica solve it?
146952
When can I say that $\cup H_i$ is a group?
100987
Let f be an r-cycle in $S_n$. Given any $h \in S_n$, show that $hfh^{-1} = (h(x_1), h(x_2), \dots, h(x_r))$
66531
$\|h(x)-h(y)\|\geq 3\|x-y\|$ prove that image of open is open
130722
Can you prove this property?
16602
Proving $M_n(I)\lhd M_n(R)$ and proofs about ideal rings.