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C00002 00002	The homomorphism theorem.
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The homomorphism theorem.

(∀f1 f2. g..f1 = f2..h ⊃ g..F1(f1)) = F2(f2)..h) ⊃ g..Y(F1) = Y(F2)..h

Here .. denotes composition of functions.

A second and easier theorem

(∀f. g..F1(f) = F2(g..f)) ⊃ g..Y(F1) = Y(F2)