Natural Deduction Fitch-style Proof
31299
Using the Fitch system, how do I prove $((p \implies q) \implies p)\implies p$?
103463
Mantel's Theorem proof verification
93410
How to prove ~ (~P & ~Q) : P ∨ Q by natural deduction
76347
Shorter proof for some equvalences
47222
Soundness of a rule of a proof system with respect to the truth tables?
92492
Natural Deduction: $(p \lor q)\to r\vdash p \to r$ and $p\to\neg q\leftrightarrow(r\lor s),\neg s\vdash (p\land \neg q)\to r$
37134
How can I solve this logic question using propositional logic (Natural deduction)?
25064
Proving the snake lemma without a diagram chase
104771
Dedekind's cut and axioms
84562
Proof using only field axioms
40048
Finding the fallacy in this broken proof
93707
Formal proof for $q \land \neg q \vdash r \land \neg r$
53056
natural deduction: introduction of universal quantifier and elimination of existential quantifier explained
17073
Using proof by contradiction vs proof of the contrapositive
121469
Proof of observations on natural numbers being expressed as differences of squares.
91861
Propositional Logic: p → q, ¬p → r, ¬q → ¬r ⊢ q
124424
How to show that there is a deduction of $\varphi\leftrightarrow\psi$