• @Some_Dumb_Goat
    link
    145 months ago

    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.