PLE treasure hunt -- Life

Multiple inheritance

Life's largest-common-subclass unification rule for classes leads to some rather strange behavior. After executing these lines:

:: red(chrominance => 30).
:: green(chrominance => 60).
:: bright(luminance => 100).

red <| color.
green <| color.

colorful(X:color) :- X.chrominance > 50.

What is the result of colorful(bright)?

Suppose we add these, presumably harmless, extra declarations:

bright_green <| bright.
bright_green <| green.

Now what is the result of colorful(bright)? Why do you think Life chose this behavior?

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Last modified: Fri Feb 2 13:47:34 "EST 1996