lean4-htt/src/Init/Data/Fin
Leonardo de Moura e0a266780b
feat: add instance Grind.CommRing (Fin n) (#8276)
This PR adds the instances `Grind.CommRing (Fin n)` and `Grind.IsCharP
(Fin n) n`. New tests:
```lean
example (x y z : Fin 13) :
    (x + y + z) ^ 2 = x ^ 2 + y ^ 2 + z ^ 2 + 2 * (x * y + y * z + z * x) := by
  grind +ring

example (x y : Fin 17) : (x + y) ^ 3 = x ^ 3 + y ^ 3 + 3 * x * y * (x + y) := by
  grind +ring

example (x y : Fin 19) : (x - y) * (x ^ 2 + x * y + y ^ 2) = x ^ 3 - y ^ 3 := by
  grind +ring
```

---------

Co-authored-by: Kim Morrison <kim@tqft.net>
2025-05-13 12:09:02 +00:00
..
Basic.lean feat: add instance Grind.CommRing (Fin n) (#8276) 2025-05-13 12:09:02 +00:00
Bitwise.lean feat: enable experimental module system in Init (#8047) 2025-04-23 17:21:33 +00:00
Fold.lean feat: enable experimental module system in Init (#8047) 2025-04-23 17:21:33 +00:00
Iterate.lean feat: enable experimental module system in Init (#8047) 2025-04-23 17:21:33 +00:00
Lemmas.lean feat: add instance Grind.CommRing (Fin n) (#8276) 2025-05-13 12:09:02 +00:00
Log2.lean feat: enable experimental module system in Init (#8047) 2025-04-23 17:21:33 +00:00