Lafari@lemmy.world to No Stupid Questions@lemmy.world · 10 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 · 10 months agomessage-square40fedilink
minus-squareSome_Dumb_Goat@pawb.sociallinkfedilinkarrow-up7·10 months agoIf A, then B If Not B, then Not A If it’s raining then the grass is wet, but you can’t tell if it’s raining if the grass is wet, because of say, a hose or sprinkler. All that you can tell is that if the grass is dry, then it is not raining, and I that’s called a contrapositive.
If A, then B
If Not B, then Not A
If it’s raining then the grass is wet, but you can’t tell if it’s raining if the grass is wet, because of say, a hose or sprinkler.
All that you can tell is that if the grass is dry, then it is not raining, and I that’s called a contrapositive.