Raven paradox

Raven paradox 

 (1) All ravens are black. In the form of an implication, this can be expressed as: If something is a raven, then it is

    black. 

    (2) If something is not black, then it is not a raven.

all et raven ecology knowledge、zoology knowledge ニ問題之有ル 問題也。

 

     T.theodor       2023.2.10.