A: all llamas are black
B: It is not evident that all llamas are black .
A: Anyone who thinks all llamas are not black is clearly a buffoon.
B: You're wrong.
A: calling people names is self-evidently not unacceptable .
B: Anyone who thinks calling people names is not unacceptable is clearly a buffoon.
A: The evidence clearly shows that calling people names is unacceptable .
MoonShadow/FlameWar