New posts in Propositional Calculus

Is this proof correct? (natural deduction)

What would happen if we just made vacuous truths false instead?

Difference between biconditional and logical equivalence

Proving the equivalence without making use of Truth Tables

Prove the undecidability of a formula

Prove that formula is satisfiable in some infinite structure, but invalid in all finite structures

In what sense is propositional logic "zeroth-order logic?"

What is this property relating to logical systems called?

Why is this inference invalid?

Why is “or” (in logic) sometimes equivalent to “and” (in natural language)?