diff options
| -rw-r--r-- | backends/lean/Base/Arith/Scalar.lean | 10 | ||||
| -rw-r--r-- | backends/lean/Base/Primitives/Scalar.lean | 7 |
2 files changed, 17 insertions, 0 deletions
diff --git a/backends/lean/Base/Arith/Scalar.lean b/backends/lean/Base/Arith/Scalar.lean index c2e4e24e..8793713b 100644 --- a/backends/lean/Base/Arith/Scalar.lean +++ b/backends/lean/Base/Arith/Scalar.lean @@ -80,4 +80,14 @@ example (x : Int) (h0 : 0 ≤ x) (h1 : x ≤ U32.max) : example (x : U32) (h0 : ¬ x = U32.ofInt 0) : 0 < x.val := by scalar_tac +/- See this: https://aeneas-verif.zulipchat.com/#narrow/stream/349819-general/topic/U64.20trouble/near/444049757 + + We solved it by removing the instance `OfNat` for `Scalar`. + Note however that we could also solve it with a simplification lemma. + However, after testing, we noticed we could only apply such a lemma with + the rewriting tactic (not the simplifier), probably because of the use + of typeclasses. -/ +example {u: U64} (h1: (u : Int) < 2): (u : Int) = 0 ∨ (u : Int) = 1 := by + scalar_tac + end Arith diff --git a/backends/lean/Base/Primitives/Scalar.lean b/backends/lean/Base/Primitives/Scalar.lean index 8fb067e1..157ade2c 100644 --- a/backends/lean/Base/Primitives/Scalar.lean +++ b/backends/lean/Base/Primitives/Scalar.lean @@ -351,10 +351,17 @@ instance [Decide (Scalar.cMin ty ≤ v ∧ v ≤ Scalar.cMax ty)] : InBounds ty @[simp] abbrev Scalar.check_bounds (ty : ScalarTy) (x : Int) : Bool := (Scalar.cMin ty ≤ x || Scalar.min ty ≤ x) ∧ (x ≤ Scalar.cMax ty || x ≤ Scalar.max ty) +/- Discussion: + This coercion can be slightly annoying at times, because if we write + something like `u = 3` (where `u` is, for instance, as `U32`), then instead of + coercing `u` to `Int`, Lean will lift `3` to `U32`). + For now we deactivate it. + -- TODO(raitobezarius): the inbounds constraint is a bit ugly as we can pretty trivially -- discharge the lhs on ≥ 0. instance {ty: ScalarTy} [InBounds ty (Int.ofNat n)]: OfNat (Scalar ty) (n: ℕ) where ofNat := Scalar.ofInt n +-/ theorem Scalar.check_bounds_imp_in_bounds {ty : ScalarTy} {x : Int} (h: Scalar.check_bounds ty x) : |