If $X$ generates $\Bbb{Q}$ then $X\setminus\{x\}$ also generates $\Bbb{Q}$
75012
Additive group of rationals has no minimal generating set
72640
$(m,n) = (\gcd(m,n))$ as ideals in $\Bbb Z$
134770
For sets $A,B$, $A \cap (B \setminus A) \subseteq \varnothing$
67926
$S_n$ is generated by elements of the form $(1k)$
120094
Prove, that for any A, B, C sets, $A\times (B\setminus C) = (A\times B)\setminus (A\times C)$ is true.
6171
Isomorphism between $\Bbb{Z}[\sqrt{d}]$ and a quotient of $\Bbb{Z}[X].$
58416
Valuations on $\Bbb Q(t)$
96845
Question: Compare the cardinality between the sets $\Bbb R$ and $\Bbb N^{\Bbb N}$
59424
Showing that $B=\{(x,y) \in \Bbb{R^2} \mid \ xy>0 \}$ is an open set
2250
What is the $x$ in $\log_b x$ called?
36631
Is $[0,1] \cap \Bbb Q$ a compact subset of $\Bbb Q$?
47856
$f(x)=ax+b$ for some $a,b\in\mathbb{Q}$ if $f(\mathbb{Q})\subset\mathbb{Q}$ and $f(\mathbb{R-Q})\subseteq \mathbb{R}-\mathbb{Q}$
25187
Why $∀x(P(x)→Q)$ is equivalent to $∃xP(x)→Q$
93017
Isomorphism between $\Bbb R$ and $\Bbb R(X)$?
33524
Prove the following $A \setminus (B\setminus C) = (A\setminus B)\cap (A \cup C)$
120642
Let $g : \Bbb N \times \Bbb N \to\Bbb N \times \Bbb N$ defined as $g(m,n) = (m + n,m - n)$
15733
Show that the cardinality of $\mathbb N$ is the same as the cardinality of $\mathbb N \times \mathbb N$