Lawgic Flashcards
Left side of the arrow
whatever symbol you place to the left of the arrow is the “Sufficient Condition”
Right side of the arrow
whatever symbol you place to the right of it is the “Necessary Condition”.
Like this: [Sufficient Condition] → [Necessary Condition]
Like this: [Sufficient Condition] → [Necessary Condition]
J > F
contrapositive: /F>/J
to create a contrapositive, you flip the symbols and negate
Step 1. Switch the two symbols around the arrow.
Step 2. Slap a negation sign on each symbol.
Step 3. There is no Step 3. It’s a two step process.
be aware of statements that already negated
D > /C
C > /D
You have to remember that when you slap a negation onto a symbol that’s already negated, the negation goes away. Negating “not selfish” becomes “selfish.”
Negation vs Opposition
Contradiction = not (X)
if =
conditional relationship
if > then
dictate a relationship that was given in a sentence.
Group 1: indicators (sufficient)
if, when (whenever), where, all, the only, every, any
- Group 1 rule: the idea immediately following the logical indicator is the sufficient condition. (introduces sufficient conditioning)
- IF I go tomorrow WHEN I don’t know WHERE, ALL I buy is THE ONLY apple for EVERY and ANY person that I like
- if this is show as the second part of a sentence then make first bc these introduce sufficient
Group 2: indicators (necessary)
ONLY, ONLY IF, ONLY WHEN, ONLY WHERE, ALWAYS, MUST, REQUIRE
- The ideas introduced by (i.e., immediately following) these words are the necessary conditions.
- if these show as first part of the sentence make it second
Group 3: indicators (negate sufficient)
UNLESS, UNTIL, OR, WITHOUT
- You pick either idea, then negate that idea, then make that idea the sufficient condition.
- in your brain transform me it to an “if” conditioning
Or
- The “inclusive or” meaning “and/or”
- The “exclusive or” meaning “or, but not both”
- Simply “and”
either or: can be…
inclusive or exclusive
Group 4: indicators
NO, NONE, NOT BOTH, NEVER, CANNOT
- You pick either idea, then negate that idea, then make that idea the necessary condition.
both Group 3 and Group 4 indicators.
You can pick either one to use as logical indicator. The other “logical indicator” becomes a negation.
