From b0dca8dbd9bc959c5ccb5355e419b03714483668 Mon Sep 17 00:00:00 2001 From: Jason Gross Date: Sat, 10 Feb 2018 15:25:59 -0500 Subject: Add some ZRange operations --- src/Util/ZRange/Operations.v | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 src/Util/ZRange/Operations.v (limited to 'src/Util/ZRange') diff --git a/src/Util/ZRange/Operations.v b/src/Util/ZRange/Operations.v new file mode 100644 index 000000000..7d9b24c40 --- /dev/null +++ b/src/Util/ZRange/Operations.v @@ -0,0 +1,36 @@ +Require Import Coq.ZArith.ZArith. +Require Import Crypto.Util.ZRange. +Require Import Crypto.Util.Notations. + +Module ZRange. + Local Open Scope zrange_scope. + + Local Notation eta v := r[ lower v ~> upper v ]. + + Definition normalize (v : zrange) : zrange + := r[ Z.min (lower v) (upper v) ~> Z.max (lower v) (upper v) ]. + + Definition abs (v : zrange) : zrange + := let (l, u) := eta v in + r[ 0 ~> Z.max (Z.abs l) (Z.abs u) ]. + + Definition two_corners (f : Z -> Z) (v : zrange) : zrange + := let (l, u) := eta v in + r[ Z.min (f l) (f u) ~> Z.max (f l) (f u) ]. + + Definition union (x y : zrange) : zrange + := let (lx, ux) := eta x in + let (ly, uy) := eta y in + r[ Z.min lx ly ~> Z.max ux uy ]. + + Definition four_corners (f : Z -> Z -> Z) (x y : zrange) : zrange + := let (lx, ux) := eta x in + union (two_corners (f lx) y) + (two_corners (f ux) y). + + Definition eight_corners (f : Z -> Z -> Z -> Z) (x y z : zrange) : zrange + := let (lx, ux) := eta x in + union (four_corners (f lx) y z) + (four_corners (f ux) y z). + +End ZRange. -- cgit v1.2.3