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Is "If A then B" equal to "B if and only if A"?
(lemmy.world)
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this post was submitted on 17 Jan 2024
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If car, then vehicle = true
Car if and only if vehicle = true.
Is this correct?
Therefore "If A then B" = "A if and only if B" (or "If B then A" = "B if and only if A")?
B can still be true when a is false. iff means that b can only be true when a is true.
Also, the equivalent statement is.
vehicle if and only if car.
not
car only if vehicle
since a truck is a vehicle, the statement is false.
Somewhat wrong above:
A B a iff b
T T T
T F F
F T F
F F T
look online for truth tables.
You’d have to firm up your definition of car and vehicle before you could decide that one. Does a hot wheels car count as a car? Does a vehicle have to be large enough to move people or freight?
Don't confuse this guy with ontological questions.
This is straight truth table level stuff.