PT9.S3.Q8-13 (Logical Operators)

Comments

• akistotle Member ⭐ 🍌🍌

  November 2017 9382 karma

  You can use either one and you will end up with the same thing.

  N cannot be in unless L is in.

  Group 3 translation:
  Step 1) The logical operator: "unless"
  Step 2) Identify the two main concepts: “N cannot be in” and “L is in”
  Step 3) Assign symbols to the two main concepts: Here, “/N” for “N cannot be in” and “L” for “L is in.”
  Step 4) Apply the translation rule: Here, pick an idea - “/N” - and negate it - “N” - and make it the sufficient condition.
  N → L

  Group 4 translation:
  Step 1) The logical operator: "cannot"
  Step 2) Identify the two main concepts: "N is in" and "unless L is in"
  Step 3) Assign symbols to the two main concepts: Here, “N” for "N is in" and "/L" for "unless L is in"
  Step 4) Apply the translation rule: Here, pick an idea - “N” - and negate it - “/N” - and make it the necessary condition.
  /L → /N

  I find Group 3 much simpler. As soon as "A cannot be in unless B is in," I immediately translate it as A → B because in order for A to be in, B must be in.
• tringo335 Alum Member ⭐

  November 2017 3679 karma

  @akistotle why does 'unless L is in' translate to '/L'?
• akistotle Member ⭐ 🍌🍌

  November 2017 edited November 2017 9382 karma

  "Unless" means "if … not" or "except if," so "unless L is in" means "the case where L is not in."
• dcdcdcdcdc Alum Member

  November 2017 edited November 2017 382 karma

  Agreed with the above. I always found it easier to think of these types of statements as the below:

  No N without L, which is equivalent to N requires L

  N --> L
• akistotle Member ⭐ 🍌🍌

  November 2017 9382 karma

  @dcdcdcdcdc said:
  Agreed with the above. I always found it easier to think of these types of statements as the below:

  No N without L, which is equivalent to N requires L

  N --> L

  Yea. I learned this thinking that all those lyrics about "I can't live without you" basically means that "I need you." lol

  So I go like, "Okay....N needs L...." whenever I see sentences like that.
• tringo335 Alum Member ⭐

  November 2017 3679 karma

  @akistotle @dcdcdcdcdc thzmks guys! I get it but it's still not cemented in my head just need more practice ugh learning this is so hard lol. So 'unless' should always be considered a / right?