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Comment by jstanley | Hacker News Reader

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jstanley

> The Mockingbird takes 2 booleans and returns True if at least one of them is True

But earlier on we were told:

> The first bird that we observe is the Mockingbird, which repeats the first word.

Can both of these things be true?

It also seems confusing that K, I, and KI are 3 different types of bird. How do you distinguish KI from KI?

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You don't need to distinguish KI (the kite) from KI (the kestrel followed by the idiot bird), because they evaluate to the same thing. Kite xy is y, and if you evaluate Kestrel Idiot xy, you get:

    KIxy -> Iy -> y

Similarly, because true is defined as K, and false as KI, if you evaluate Mxy where x and y are K or KI, and keep evaluating, you'll eventually end up with either K or KI, depending on whether (x or y) is true or false. I agree, though, that is confusing that the post didn't explain any of this; I assume it's not finished yet.

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