New posts in formal-proofs

Clarification regarding substitution in sequent calculus

logic quantifiers proof-theory formal-proofs sequent-calculus

Status of declarative proof languages in proof assistants

formal-proofs automated-theorem-proving theorem-provers

Different proof that $\sqrt{2}$ is irrational

elementary-number-theory irrational-numbers formal-proofs

Natural Deduction Tautology

logic propositional-calculus natural-deduction formal-proofs

What is the theorem that has the most proofs?

soft-question big-list formal-proofs

How do I prove Separation Schema within ZFC?

logic set-theory formal-proofs

Motivation for natural deduction

logic soft-question natural-deduction formal-proofs

⊢∃𝑥(𝜙⟹∀𝑥𝜙) using Hilbert-style proof [duplicate]

logic first-order-logic predicate-logic formal-proofs

What is "magic" about the combination of addition and multiplication in formal arithmetic?

logic incompleteness formal-proofs

How to justify claims on the complexity of formal proofs without definitions, as described in "Type Theory and Formal Proof" by Nederpelt and Geuvers

formal-proofs type-theory

Calculus of Natural Deduction That Works for Empty Structures

logic proof-theory formal-proofs natural-deduction formal-systems

Given ∃x.¬p(x), use the Fitch System to prove ¬∀x.p(x).

logic predicate-logic first-order-logic natural-deduction formal-proofs

Proof of transitivity in Hilbert Style

logic predicate-logic formal-proofs

Each person has at most 3 enemies in a group. Show that we can separate them into two groups where a person will have at most one enemy in the group.

combinatorics graph-theory algorithms puzzle formal-proofs

Showing that $\lim_{x\to c} f(x) > \alpha \Rightarrow f(c+h) > \alpha$ for $|h| < \delta $ where $\delta > 0 $

limits continuity proof-writing formal-proofs

When writing proofs, is logical notation a crutch?

logic soft-question formal-proofs

Prove $( \lnot C \implies \lnot B) \implies (B \implies C)$ without the Deduction Theorem

logic propositional-calculus formal-proofs

natural deduction: introduction of universal quantifier and elimination of existential quantifier explained

logic proof-theory formal-proofs natural-deduction formal-systems

Should a mathematical proof be 'convincing'?

proof-writing philosophy formal-proofs