Claim: Using Fuzzy concepts (a very recent concept) to define sandwiches, a peanut butter and jelly sandwich has an unweighted score of 1 and is not categorized as a sandwich, while a hamburger without bun has an unweighted score of 7, and is categorized as a sandwich.
Evidence: Peanut butter and jelly sandwich 7 
Peanut butter and jelly sandwich Sandwich Hamburger without bun 1 
Hamburger without bun Burger (patty) with toppings 1