You asked the same question that is in all three of the 'fuzzy logic" mathematic books I own.

But you lied: it isn't easier, it's a harder question.

At what point does a comfy chair become a love-seat? At which point does it become a couch? I've seen chairs with solid bases and chairs with five legs. What happens if a leg breaks: is it still a chair?

Simpler question my left wedding-tackle! It's exactly the reason why we are so far away from real AI.