For this posting, let's just take our first example of a derivation, a deduction with a sequence of conclusions, and put it into our old Araucaria form. As described in the beginning of the tutorial, this argument takes two of our familiar forms and puts them together. This can be represented like any complex argument of the type described in 1.4.
So, take the scheme set from 1.1: that's 1_1.scm (or you can use 2_1.scm just as well) to label the complex argument that results from putting these two inferences together. Note that you'll use two different valid argument forms from 1.1 to label the two separate inferences all on one tree. (If you don't get the idea at first, think about it, discuss it in your group, ask about in under W4 problems, or just call me!
If he's to get an 'A', he must turn in informal proofs.
But he doesn't turn in the informal proofs.
So, he won't get an 'A'.
Chris will get either an 'A' or a 'B'.
We just concluded that he won't get an 'A'.
So, we can further conclude, he will get a 'B'.
So, for postings:
Your end result will look a little like this:
But will the premises be related to the conclusion independently? or collaboratively (as pictued)? See 1.4 for hints.