A valid deductive argument form where if a disjunction (P or Q) is true and one disjunct (P) is false,…
The disjunction introduction rule states that from any single proposition, one can infer a disjunction including that proposition and any…
Disjunction elimination, also known as proof by cases, is a fundamental rule of inference. It allows concluding a statement R…
A derivable rule is a logical rule that can be derived from the existing axioms and inference rules of a…
A cut rule in proof theory introduces an intermediate conclusion within a deductive proof. This intermediate step is then utilized…
Contraposition is a logical principle establishing the equivalence between a conditional statement and its contrapositive. It transforms 'If P, then…
Learn about the conjunction introduction, a fundamental rule of inference in logic. It permits combining two separate statements into a…
Conjunction elimination is a fundamental rule of inference in propositional logic. It permits the deduction of a single conjunct from…
A robust form of reductio ad absurdum, it proves a proposition P by demonstrating that its negation ¬P leads to…
The addition rule in formal logic allows inferring a disjunction from a single proposition. It states that if P is…