From e49b92903cbd3dc7c981789cb4121dc89569bed3 Mon Sep 17 00:00:00 2001 From: Ryan Lahfa Date: Tue, 23 Apr 2024 14:59:48 +0200 Subject: feat(backends/lean): scalars form a linear order More than c1c33de8, actually, scalars form a linear order with a decidable ≤ operation which is induced by the integer (Z) model. Signed-off-by: Ryan Lahfa --- backends/lean/Base/Primitives/Scalar.lean | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'backends/lean') diff --git a/backends/lean/Base/Primitives/Scalar.lean b/backends/lean/Base/Primitives/Scalar.lean index be930754..014decb1 100644 --- a/backends/lean/Base/Primitives/Scalar.lean +++ b/backends/lean/Base/Primitives/Scalar.lean @@ -1404,6 +1404,21 @@ instance (ty: ScalarTy) : Preorder (Scalar ty) where trans (a: Int) ≤ (b: Int) ∧ ¬ (b: Int) ≤ (a: Int); exact lt_iff_le_not_le repeat rewrite [← Scalar.le_equiv]; rfl +instance (ty: ScalarTy) : PartialOrder (Scalar ty) where + le_antisymm := fun a b Hab Hba => Scalar.eq_imp _ _ ((@le_antisymm Int _ _ _ ((Scalar.le_equiv a b).1 Hab) ((Scalar.le_equiv b a).1 Hba))) + +instance ScalarDecidableLE (ty: ScalarTy) : DecidableRel (· ≤ · : Scalar ty -> Scalar ty -> Prop) := by + simp [instLEScalar] + -- Lift this to the decidability of the Int version. + infer_instance + +instance (ty: ScalarTy) : LinearOrder (Scalar ty) where + le_total := fun a b => by + rcases (Int.le_total a b) with H | H + left; exact (Scalar.le_equiv _ _).2 H + right; exact (Scalar.le_equiv _ _).2 H + decidableLE := ScalarDecidableLE ty + -- Leading zeros def core.num.Usize.leading_zeros (x : Usize) : U32 := sorry def core.num.U8.leading_zeros (x : U8) : U32 := sorry -- cgit v1.2.3