∀A,B:Type. ({() ⊢ _:Equiv(discr(A);discr(B))}
A ~ B)
{ Auto }
1. A : Type
2. B : Type
3. {() ⊢ _:Equiv(discr(A);discr(B))}
⊢ A ~ B
3. A ~ B
⊢ {() ⊢ _:Equiv(discr(A);discr(B))}