The weakening rule allows adding propositions to a logical derivation without invalidating it. This principle confirms that if a conclusion…
The necessitation rule in modal logic states that if a proposition is provable (a theorem), then its necessity is also…
The disjunction introduction rule states that from any single proposition, one can infer a disjunction including that proposition and any…
A cut rule in proof theory introduces an intermediate conclusion within a deductive proof. This intermediate step is then utilized…