discussion online derivation and justification exercise

This assignment features three proofs, Alpha, Beta, and Gamma, with three premises each. Each conclusion can be derived in 4 additional steps.

In the Logic Labs, students select the correct answer from a list of choices to fill in blanks in given proofs. Here, students must fill in all the blanks–4 derivations & 4 justifications–for each proof. Remember, Discussion Assignments are meant to challenge while Logic Labs are meant to train you: both are important learning practices.

Remember, it is easier to figure out proofs on paper, first, then enter your answers into Blackboard. Recall also that you should cut and paste these symbols into your answers but that the symbols are easier to paste in after you have typed in your atomic letters and parentheses (if needed):

≡⊃•∨

If you need a tilde use the one on your keyboard or cut and paste this one: ~

Finally, be sure to use CAPITAL LETTERS to state the abbreviation of each rule in the justification followed by the line number or numbers that instantiate that form.

If there are two line numbers, list the lower number first, then a comma, then a space, then the higher number. For example: “MT 6, 7” is correct. These versions of this derivation are incorrect: “modus tollens 6 & 7” “6 & 7 MT” “MT 7, 6” and so on. The order of the line numbers does not matter from a logical perspective but in order to make the correct answers match in Blackboard, we adopt this convention.