Finding a derivation of $\vdash{(\lnot\lnot{p}\to{p})}$
32929
Questions about proving $\lnot \lnot a = a$
131257
$\to$ vs. $\vdash$ in logic
125966
Why there's a finite $\Gamma '$ such that $\Gamma ' \vDash \varphi$?
123602
Non integer derivative of $1/p(x)$
152932
Proof: $\det\pmatrix{\langle v_i , v_j \rangle}\neq0$ $\iff \{v_1,\dots,v_n\}~\text{l.i.}$
15596
Identification of each tangent space $T_pV$ with $V$ itself?
145462
On the canonical isomorphism between $V$ and $V^{**}$
146339
Proof of -(-v)=v in a vector space
71187
How to prove $\hat{p}|x\rangle=i\hbar\frac{\partial}{\partial x}|x\rangle$,using $[\hat{x},\hat{p}]=i\hbar$?
89089
Prove that there is a unique inner product on $V$
90055
Show that $\mathcal P(x)\notin x$
20789
If $\Sigma \vdash \varphi$ then $\Sigma \vdash \forall x \varphi$. Why when $(\varphi \implies \forall x \varphi)$ is not true?
14778
Derivation of uncertainty propagation?
49296
Prove $|(1+|u|^2)v-(1+|v|^2)u|>|u\bar{v}-\bar{u}v|$
157213
Application of Luca's theorem
108837
How to show that $\vdash (\forall x \beta \to \alpha) \leftrightarrow \exists x (\beta \to \alpha)$?
66501
Notation Question: What does $\vdash$ mean in logic?