Use rules of implication, rules of replacement, conditional proofs and/or indirect proofs, to prove the arguments (or tautologies) valid. Be sure to justify every line you provide with both line numbers and the applicable rule. If you can't access the logical operation signs, just write "dot," "wedge", "horseshoe" or "triple bar" wherever applicable. 1. ( R ∨ S ) ⊃ ( T ⊃ K )
2. ~ K 3. R / ~ T