New posts in propositional-calculus

Still struggling to understand vacuous truths

logic definition proof-explanation propositional-calculus boolean-algebra

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

logic soft-question definition propositional-calculus

Equivalence of $a \rightarrow b$ and $\lnot a \vee b$ [closed]

logic propositional-calculus

What an implication means when stating the solutions of an equation?

discrete-mathematics logic propositional-calculus first-order-logic predicate-logic

"Modus moron" rule of inference?

propositional-calculus natural-deduction

Using "implies" to refer to material conditional

logic terminology definition propositional-calculus predicate-logic

Conditional Statements: "only if"

logic propositional-calculus

Is my approach to showing $(\exists y\in B\cap C)\Rightarrow(x\in A)$ correct?

elementary-set-theory logic proof-writing solution-verification propositional-calculus

Assumed True until proven False. The Curious Case of the Vacuous Truth

logic propositional-calculus

Is my approach to showing $(x\in A)\Rightarrow(\exists y\in B\cap C)$ correct?

elementary-set-theory logic proof-writing solution-verification propositional-calculus

Using proof by contradiction vs proof of the contrapositive

discrete-mathematics logic propositional-calculus

In classical logic, why is $(p\Rightarrow q)$ True if $p$ is False and $q$ is True?

logic propositional-calculus

Can every proof by contradiction also be shown without contradiction?

logic proof-writing propositional-calculus proof-theory

In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?

logic propositional-calculus