Why is $S_{\ast}\left(X,A\right)$ free?
70298
Are quotients of chain groups $C_n(X)/C_n(A)$ still free?
59187
Proof, is $\forall x : (P(x) \lor Q(x)) \Leftrightarrow \forall x : P(x) \lor \forall x : Q(x)$?
82788
Direct summand of a free module
14158
Prove that $R$ is an integral domain $\Leftrightarrow$ $R[x]$ is an integral domain
7384
How do I prove that $m(TE)=\left|\det(T)\right|m(E)$?
76685
Determine $\text{Aut}(S)$ where $S = \mathbb{Q}[x]/(x^2)$
149801
prove that $TS = ST$
151910
Why is $K^{\ast n}$ contained in the norm group?
80996
A canonical construction proving $\left|HK\right| = \left|H\right|\left|K\right| / \left|H \cap K\right|$?
26678
The meaning of $\rightsquigarrow$ in math?
47434
Proof that $A \subseteq B \Leftrightarrow A \cup B = B$
123282
free product with amalgamation is correspondingly a pushout
82739
Why is $\alpha \rightarrow \forall x(\alpha)$ not generally correct in first-order logic?
49385
Proving $\forall x (A\to B) \to(A \to \forall x B):x\notin \mbox{free}(A)$ in a Hilbert system where it is not an axiom
154363
Prove that $\text{aff}(X) = \text{aff}(\text{closure}(X))$
106101
Why there is much interest in the study of $\operatorname{Gal}\left(\overline{\mathbb Q}/\mathbb Q\right)$?
34398
Prove $\left| \int_a^b f(t) dt \right| \leq \int_a^b \left| f(t) \right| dt$