Lafari@lemmy.world to No Stupid Questions@lemmy.world · 8 months agoIs "If A then B" equal to "B if and only if A"?message-squaremessage-square40fedilinkarrow-up138arrow-down110
arrow-up128arrow-down1message-squareIs "If A then B" equal to "B if and only if A"?Lafari@lemmy.world to No Stupid Questions@lemmy.world · 8 months agomessage-square40fedilink
minus-squareLafari@lemmy.worldOPlinkfedilinkarrow-up1·8 months agoIf 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”)?
minus-squarezenharbinger@lemmy.worldlinkfedilinkarrow-up6·edit-28 months agoB 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.
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.