New posts in Formal Proofs

What's up with the Sheffer stroke axiom?

Is this a correct natural deduction proof?

Everyone loves all lovers, Romeo loves Juliet $\vdash$ I love you (Natural deduction proof)

What is so funny about sin($\alpha+\beta$) versus sin(s+i+n)?

How can we express "induction is the same as recursion", formally?

Understanding ex falso quodlibet together with proof by contradiction in a Gentzen style ND Proof

Trouble understanding proof to $\vdash ((\neg(\phi\rightarrow \psi))\rightarrow\phi)$?

Is this proof correct? (natural deduction)

Use Fitch system to proof ((p ⇒ q) ⇒ p) ⇒ p without any premise. ONLY FOR FITCH SYSTEM.

When writing proofs, is logical notation a crutch?