diff -r 962c8e346ab9 -r 4e80fb049dca src/bisection_tree/aggregator.rs
--- a/src/bisection_tree/aggregator.rs	Sun Apr 27 15:45:40 2025 -0500
+++ b/src/bisection_tree/aggregator.rs	Sun Apr 27 15:56:43 2025 -0500
@@ -2,8 +2,7 @@
 Aggregation / summarisation of information in branches of bisection trees.
 */
 
-use crate::instance::Instance;
-use crate::sets::Set;
+pub use crate::bounds::Bounds;
 use crate::types::*;
 
 /// Trait for aggregating information about a branch of a [bisection tree][super::BT].
@@ -56,144 +55,6 @@
     }
 }
 
-/// Upper and lower bounds on an `F`-valued function.
-#[derive(Copy, Clone, Debug)]
-pub struct Bounds<F>(
-    /// Lower bound
-    pub F,
-    /// Upper bound
-    pub F,
-);
-
-impl<F: Copy> Bounds<F> {
-    /// Returns the lower bound
-    #[inline]
-    pub fn lower(&self) -> F {
-        self.0
-    }
-
-    /// Returns the upper bound
-    #[inline]
-    pub fn upper(&self) -> F {
-        self.1
-    }
-}
-
-impl<F: Float> Bounds<F> {
-    /// Returns a uniform bound.
-    ///
-    /// This is maximum over the absolute values of the upper and lower bound.
-    #[inline]
-    pub fn uniform(&self) -> F {
-        let &Bounds(lower, upper) = self;
-        lower.abs().max(upper.abs())
-    }
-
-    /// Construct a bounds, making sure `lower` bound is less than `upper`
-    #[inline]
-    pub fn corrected(lower: F, upper: F) -> Self {
-        if lower <= upper {
-            Bounds(lower, upper)
-        } else {
-            Bounds(upper, lower)
-        }
-    }
-
-    /// Refine the lower bound
-    #[inline]
-    pub fn refine_lower(&self, lower: F) -> Self {
-        let &Bounds(l, u) = self;
-        debug_assert!(l <= u);
-        Bounds(l.max(lower), u.max(lower))
-    }
-
-    /// Refine the lower bound
-    #[inline]
-    pub fn refine_upper(&self, upper: F) -> Self {
-        let &Bounds(l, u) = self;
-        debug_assert!(l <= u);
-        Bounds(l.min(upper), u.min(upper))
-    }
-}
-
-impl<'a, F: Float> std::ops::Add<Self> for Bounds<F> {
-    type Output = Self;
-    #[inline]
-    fn add(self, Bounds(l2, u2): Self) -> Self::Output {
-        let Bounds(l1, u1) = self;
-        debug_assert!(l1 <= u1 && l2 <= u2);
-        Bounds(l1 + l2, u1 + u2)
-    }
-}
-
-impl<'a, F: Float> std::ops::Mul<Self> for Bounds<F> {
-    type Output = Self;
-    #[inline]
-    fn mul(self, Bounds(l2, u2): Self) -> Self::Output {
-        let Bounds(l1, u1) = self;
-        debug_assert!(l1 <= u1 && l2 <= u2);
-        let a = l1 * l2;
-        let b = u1 * u2;
-        // The order may flip when negative numbers are involved, so need min/max
-        Bounds(a.min(b), a.max(b))
-    }
-}
-
-impl<F: Float> std::iter::Product for Bounds<F> {
-    #[inline]
-    fn product<I>(mut iter: I) -> Self
-    where
-        I: Iterator<Item = Self>,
-    {
-        match iter.next() {
-            None => Bounds(F::ZERO, F::ZERO),
-            Some(init) => iter.fold(init, |a, b| a * b),
-        }
-    }
-}
-
-impl<F: Float> Set<F> for Bounds<F> {
-    fn contains<I: Instance<F>>(&self, item: I) -> bool {
-        let v = item.own();
-        let &Bounds(l, u) = self;
-        debug_assert!(l <= u);
-        l <= v && v <= u
-    }
-}
-
-impl<F: Float> Bounds<F> {
-    /// Calculate a common bound (glb, lub) for two bounds.
-    #[inline]
-    pub fn common(&self, &Bounds(l2, u2): &Self) -> Self {
-        let &Bounds(l1, u1) = self;
-        debug_assert!(l1 <= u1 && l2 <= u2);
-        Bounds(l1.min(l2), u1.max(u2))
-    }
-
-    /// Indicates whether `Self` is a superset of the argument bound.
-    #[inline]
-    pub fn superset(&self, &Bounds(l2, u2): &Self) -> bool {
-        let &Bounds(l1, u1) = self;
-        debug_assert!(l1 <= u1 && l2 <= u2);
-        l1 <= l2 && u2 <= u1
-    }
-
-    /// Returns the greatest bound contained by both argument bounds, if one exists.
-    #[inline]
-    pub fn glb(&self, &Bounds(l2, u2): &Self) -> Option<Self> {
-        let &Bounds(l1, u1) = self;
-        debug_assert!(l1 <= u1 && l2 <= u2);
-        let l = l1.max(l2);
-        let u = u1.min(u2);
-        debug_assert!(l <= u);
-        if l < u {
-            Some(Bounds(l, u))
-        } else {
-            None
-        }
-    }
-}
-
 impl<F: Float> Aggregator for Bounds<F> {
     #[inline]
     fn aggregate<I>(&mut self, aggregates: I)