Use the Proof Builder to complete a natural deduction proof. For this proof, you are permitted to use the 18 propositional rules of inference, conditional and indirect proof, universal instantiation (UI), universal generalization (UG), existential instantiation (EI), existential generalization (EG), quantifier negation (QN), and the identity rule (Id). Be careful not to violate any of the restrictions on the predicate logic rules of inference.
Enter line numbers as a comma-separated list of numbers or range like 3-7. If line numbers are not needed to justify a line of the proof, leave that box blank. Use indentation to indicate any conditional or indirect proof sequences. You can use the check line button () to check each line of your proof individually. When your proof is complete, click "CHECK PROOF."