Is "If A then B" equal to "B if and only if A"?

Lafari@lemmy.world to No Stupid Questions@lemmy.world – 40 points –
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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.