Lesson 28 of 40 Introduction to logic , @ 2 minutes 28 sec to 2 minutes 34 sec

Maestro_eba

When JY is explaining not ( group 4 Logical operator) he does not apply the not to the come home idea. i understand its function as a logical operator but why doesn't not affix itself to /CH as in the description of Group 3.

if not is the L.O. and u have to negate the second idea, but it seems to me the the properties of not should apply to the ( 1st idea) come home idea!

Obijuan, please explain!

Pacifico

Okay so in this video he is specifically breaking down when both group 3 and group 4 logical indicators appear in the same sentence. The first half of the video he uses "until" as the group 3 indicator and "not" as the negation of "come home". In the second half of the video he uses "not" as the group 4 indicator and "until" as the negation of "you've made money". He is just showing that either approach will lead you to the same translation. I think for most people looking at sentences like this, it is more intuitive to use "until" as the logical indicator and use "not" as the negation, since "until" doesn't evoke negation in people's minds in the same way that "not" does.

I hope this answers your question, but if not, let me know and I'll try to explain it in a different way. It sounds to me like you understand the first way, but have trouble with the second way. It's important to remember they're essentially doing the same thing, but one is more naturally intuitive, as it seems you have recognized.