$R[x]$ has a subring isomorphic to $R$
121465
$R[x]$ has a subring isomorphic to $R$.
29359
Localisation isomorphic to a quotient of polynomial ring
74663
Is $\mathbb{R}$ an algebraic extension of some proper subfield?
45627
Find a sub-ring of M(2, $\mathbb{Q}$) which is isomorphic to $\mathbb{Q}$
42652
Must $k$-subalgebra of $k[x]$ be finitely generated?
73652
Exhibiting an isomorphism between two finite fields
52088
Isomorphism of an endomorphism ring, how can $R\cong R^2$?
55902
Show $R[x]/(x)\cong R$
115541
Subrings of polynomial rings over the complex plane
39576
Quotient ring being isomorphic to the initial ring
14158
Prove that $R$ is an integral domain $\Leftrightarrow$ $R[x]$ is an integral domain
148881
Aut(GxH) isomorphic to Aut(G)xAut(H)
44983
Isomorphism of R-modules
158311
What is the dimension of $R[[X]]$ where $R$ is a Noetherian ring?
83009
Showing that $R(x)$ is a proper subset of $R((x))$ if $R$ is a field
91222
Isomorphism between $\mathfrak o(4,\mathbb R)$ and $\mathfrak o (3,\mathbb R) \oplus\mathfrak o (3,\mathbb R) $
106894
If a subring of a ring R has identity, does R also have the identity?