Inference rule 56: Double negation elimination (declared)
Given that the double negation \neg \neg \phi holds, we may infer that \phi holds: \cfrac{\vdash \neg \neg \phi}{\vdash \phi}.
A theoretical quest.
Inference rule 56: Double negation elimination (declared)
Given that the double negation \neg \neg \phi holds, we may infer that \phi holds: \cfrac{\vdash \neg \neg \phi}{\vdash \phi}.