Hi - the thread below talks about this, actually!

This one really confused me but I think it was because I made an assumption that is not correct and I'll share in case some other people did so too.

Previously they told us the rule of (simplified for ease): A + B + C + D -> E

But then in P's example we see:

premise: pA + pB

conclusion: pC + pD -> pE

My mistake was that I used the logic of the rule we were told in the lesson previously. What I should have done is consider p's premise/conclusion without the previous rule.

with p's premise/conclusion alone we see that somehow we are supposed to be convinced that pC + pD -> pE with no connection from pA + pB.

SOOOO we would need the previous rule for it to make sense and for there to be the connection between (pA + pB) AND (pC + pD -> pE) because p's scenario doesn't give us that, which is the missing rule

After it's KIUd, it says

premise: A + B + C + D

conclusion: E

but how did we get there? hence, the missing rule.

The missing rule is the A + B + C + D -> E because now all the pieces are connected, which P's part didn't do

If this is totally off base please let me know lol! But maybe my confusion can help someone else