diff --git a/src/entity.rs b/src/entity.rs
index be31660..3f10f8b 100644
--- a/src/entity.rs
+++ b/src/entity.rs
@@ -1,8 +1,8 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 
+use crate::math::eqn::Eqns;
 use crate::math::{Point2, Region, Region1, Region2, Scalar};
-use crate::math::eqn::{Eqns};
 use std::fmt;
 
 type EntityId = i64;
@@ -14,7 +14,9 @@ pub struct Constrainable<T: Clone, TRegion: Region<T>> {
     constraints: TRegion,
 }
 
-impl<T: Clone + fmt::Display, TRegion: Region<T> + fmt::Display> fmt::Display for Constrainable<T, TRegion> {
+impl<T: Clone + fmt::Display, TRegion: Region<T> + fmt::Display> fmt::Display
+    for Constrainable<T, TRegion>
+{
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{{ {} ∈ {} }}", self.value, self.constraints)
     }
@@ -22,7 +24,11 @@ impl<T: Clone + fmt::Display, TRegion: Region<T> + fmt::Display> fmt::Display fo
 
 impl<T: Clone, TRegion: Region<T> + Clone> Constrainable<T, TRegion> {
     pub fn new(value: T, constraints: TRegion) -> Self {
-        Self { id: 0, value, constraints }
+        Self {
+            id: 0,
+            value,
+            constraints,
+        }
     }
 
     pub fn new_full(value: T) -> Self {
diff --git a/src/main.rs b/src/main.rs
index 3e7889d..ae784b5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,7 +18,7 @@ mod relation;
 
 fn main() {
     use entity::{CPoint, PointRef};
-    use math::{Point2, Expr, Region2, Rot2, Eqn, Eqns};
+    use math::{Eqn, Eqns, Expr, Point2, Region2, Rot2};
     use relation::{Relation, ResolveResult};
 
     env_logger::init();
@@ -30,14 +30,21 @@ fn main() {
     // let u2 = eqn::Expr::from(1.);
     let origin = CPoint::new_single(Point2::new((0.).into(), (0.).into())).into_ref();
     // let p1 = Point::new_ref(Var::new_full(Point2::new((1.).into(), (1.).into())));
-    let p1 = CPoint::new(Point2::new(0.,0.), Region2::Singleton(Point2::new((u1).into(), (u2).into()))).into_ref();
+    let p1 = CPoint::new(
+        Point2::new(0., 0.),
+        Region2::Singleton(Point2::new((u1).into(), (u2).into())),
+    )
+    .into_ref();
     let p2 = CPoint::new_full(Point2::new((4.).into(), (4.).into())).into_ref();
     let p3 = CPoint::new_full(Point2::new((2.).into(), (2.).into())).into_ref();
     let mut points: Vec<PointRef> = vec![origin.clone(), p1.clone(), p2.clone(), p3.clone()];
     let print_points = |points: &Vec<PointRef>| {
         println!(
             "origin: {}\np1: {}\np2: {}\np3: {}",
-            points[0].borrow(), points[1].borrow(), points[2].borrow(), points[3].borrow(),
+            points[0].borrow(),
+            points[1].borrow(),
+            points[2].borrow(),
+            points[3].borrow(),
         );
     };
     print_points(&points);
@@ -49,8 +56,12 @@ fn main() {
     let c3 = relation::PointAngle::new_horizontal(p2.clone(), p3.clone());
     let c2 = relation::AlignedDistance::new_vertical(p1.clone(), p2.clone(), 12.);
     let c5 = relation::PointAngle::new(p1.clone(), p3.clone(), Rot2::from_angle_deg(0.572938698));
-    let mut relations: Vec<Box<dyn Relation>> =
-        vec![/*Box::new(c1),*/ Box::new(c2), Box::new(c3), Box::new(c4), Box::new(c5)];
+    let mut relations: Vec<Box<dyn Relation>> = vec![
+        /*Box::new(c1),*/ Box::new(c2),
+        Box::new(c3),
+        Box::new(c4),
+        Box::new(c5),
+    ];
     let mut constrained: Vec<Box<dyn Relation>> = Vec::new();
     let mut any_underconstrained = true;
     let mut any_constrained = true;
diff --git a/src/math/eqn.rs b/src/math/eqn.rs
index 154e767..a9ff202 100644
--- a/src/math/eqn.rs
+++ b/src/math/eqn.rs
@@ -1,8 +1,8 @@
 use std::fmt;
 
-use super::Scalar;
 use super::expr::Expr;
 use super::unknown::*;
+use super::Scalar;
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct Eqn(pub Expr, pub Expr);
diff --git a/src/math/expr.rs b/src/math/expr.rs
index 2ab68e8..3e52633 100644
--- a/src/math/expr.rs
+++ b/src/math/expr.rs
@@ -1,9 +1,9 @@
 use std::collections::BTreeMap;
 use std::fmt;
 
-use super::Scalar;
 use super::eqn::Eqns;
-use super::unknown::{Unknown, Unknowns, UnknownSet};
+use super::unknown::{Unknown, UnknownSet, Unknowns};
+use super::Scalar;
 
 #[derive(Clone, Debug, PartialEq)]
 pub enum Expr {
@@ -127,11 +127,11 @@ fn product_fold(l: Expr, r: Expr) -> Expr {
         (Product(mut ls), Product(mut rs)) => {
             ls.append(&mut rs);
             Product(ls)
-        },
+        }
         (Product(mut ps), o) | (o, Product(mut ps)) => {
             ps.push(o);
             Product(ps)
-        },
+        }
         (l, r) => Expr::new_product(l, r),
     }
 }
@@ -143,22 +143,20 @@ fn group_product(es: Exprs) -> Exprs {
     let mut other = Exprs::new();
     for e in es {
         let unkns = e.unknowns();
-        match e { 
+        match e {
             Const(c) => match consts {
                 None => consts = Some(c),
                 Some(cs) => consts = Some(c * cs),
-            }
-            e => {
-                other.push(e)
-            }
+            },
+            e => other.push(e),
         }
     }
-    if let Some(cs) = consts { 
+    if let Some(cs) = consts {
         if relative_eq!(cs, 0.0) {
             other.clear();
             other.push(Const(0.0))
         } else if relative_ne!(cs, 1.0) {
-            other.push(Const(cs)) 
+            other.push(Const(cs))
         }
     };
     trace!("group product: {:?} => {:?}", es2, other);
@@ -457,4 +455,4 @@ impl fmt::Display for Expr {
             Neg(e) => write!(f, "-({})", e),
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/math/mod.rs b/src/math/mod.rs
index e36076f..96fcbab 100644
--- a/src/math/mod.rs
+++ b/src/math/mod.rs
@@ -1,4 +1,3 @@
-
 pub mod eqn;
 pub mod expr;
 pub mod ops;
@@ -8,9 +7,9 @@ pub mod vec;
 
 pub use eqn::{Eqn, Eqns};
 pub use expr::{Expr, Exprs};
-pub use unknown::{Unknown, Unknowns, UnknownSet};
-pub use region::{Region, Region1, Line2, Region2, GenericRegion};
 pub use ops::*;
+pub use region::{GenericRegion, Line2, Region, Region1, Region2};
+pub use unknown::{Unknown, UnknownSet, Unknowns};
 pub use vec::*;
 
 pub type Scalar = f64;
diff --git a/src/math/ops.rs b/src/math/ops.rs
index 6a03ed7..176857c 100644
--- a/src/math/ops.rs
+++ b/src/math/ops.rs
@@ -3,195 +3,195 @@ use std::ops;
 use super::{Expr, Scalar, Unknown};
 
 impl From<Scalar> for Expr {
-  fn from(c: Scalar) -> Expr {
-    Expr::Const(c)
-  }
+    fn from(c: Scalar) -> Expr {
+        Expr::Const(c)
+    }
 }
 
 impl From<Unknown> for Expr {
-  fn from(u: Unknown) -> Expr {
-    Expr::Unkn(u)
-  }
+    fn from(u: Unknown) -> Expr {
+        Expr::Unkn(u)
+    }
 }
 
 impl ops::Add<Expr> for Expr {
-  type Output = Expr;
-  fn add(self, rhs: Expr) -> Expr {
-    Expr::new_sum(self, rhs)
-  }
+    type Output = Expr;
+    fn add(self, rhs: Expr) -> Expr {
+        Expr::new_sum(self, rhs)
+    }
 }
 
 impl ops::Add<Scalar> for Expr {
-  type Output = Expr;
-  fn add(self, rhs: Scalar) -> Expr {
-    Expr::new_sum(self, rhs.into())
-  }
+    type Output = Expr;
+    fn add(self, rhs: Scalar) -> Expr {
+        Expr::new_sum(self, rhs.into())
+    }
 }
 
 impl ops::Add<Unknown> for Expr {
-  type Output = Expr;
-  fn add(self, rhs: Unknown) -> Expr {
-    Expr::new_sum(self, rhs.into())
-  }
+    type Output = Expr;
+    fn add(self, rhs: Unknown) -> Expr {
+        Expr::new_sum(self, rhs.into())
+    }
 }
 
 impl ops::Sub<Expr> for Expr {
-  type Output = Expr;
-  fn sub(self, rhs: Expr) -> Expr {
-    Expr::new_minus(self, rhs)
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Expr) -> Expr {
+        Expr::new_minus(self, rhs)
+    }
 }
 
 impl ops::Sub<Scalar> for Expr {
-  type Output = Expr;
-  fn sub(self, rhs: Scalar) -> Expr {
-    Expr::new_minus(self, rhs.into())
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Scalar) -> Expr {
+        Expr::new_minus(self, rhs.into())
+    }
 }
 
 impl ops::Sub<Unknown> for Expr {
-  type Output = Expr;
-  fn sub(self, rhs: Unknown) -> Expr {
-    Expr::new_minus(self, rhs.into())
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Unknown) -> Expr {
+        Expr::new_minus(self, rhs.into())
+    }
 }
 
 impl ops::Mul<Expr> for Expr {
-  type Output = Expr;
-  fn mul(self, rhs: Expr) -> Expr {
-    Expr::new_product(self, rhs)
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Expr) -> Expr {
+        Expr::new_product(self, rhs)
+    }
 }
 
 impl ops::Mul<Scalar> for Expr {
-  type Output = Expr;
-  fn mul(self, rhs: Scalar) -> Expr {
-    Expr::new_product(self, rhs.into())
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Scalar) -> Expr {
+        Expr::new_product(self, rhs.into())
+    }
 }
 
 impl ops::Mul<Unknown> for Expr {
-  type Output = Expr;
-  fn mul(self, rhs: Unknown) -> Expr {
-    Expr::new_product(self, rhs.into())
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Unknown) -> Expr {
+        Expr::new_product(self, rhs.into())
+    }
 }
 
 impl ops::Div<Expr> for Expr {
-  type Output = Expr;
-  fn div(self, rhs: Expr) -> Expr {
-    Expr::new_div(self, rhs)
-  }
+    type Output = Expr;
+    fn div(self, rhs: Expr) -> Expr {
+        Expr::new_div(self, rhs)
+    }
 }
 
 impl ops::Div<Scalar> for Expr {
-  type Output = Expr;
-  fn div(self, rhs: Scalar) -> Expr {
-    Expr::new_div(self, rhs.into())
-  }
+    type Output = Expr;
+    fn div(self, rhs: Scalar) -> Expr {
+        Expr::new_div(self, rhs.into())
+    }
 }
 
 impl ops::Div<Unknown> for Expr {
-  type Output = Expr;
-  fn div(self, rhs: Unknown) -> Expr {
-    Expr::new_div(self, rhs.into())
-  }
+    type Output = Expr;
+    fn div(self, rhs: Unknown) -> Expr {
+        Expr::new_div(self, rhs.into())
+    }
 }
 
 impl ops::Neg for Expr {
-  type Output = Expr;
-  fn neg(self) -> Expr {
-    Expr::new_neg(self)
-  }
+    type Output = Expr;
+    fn neg(self) -> Expr {
+        Expr::new_neg(self)
+    }
 }
 
 impl ops::Add<Expr> for Unknown {
-  type Output = Expr;
-  fn add(self, rhs: Expr) -> Expr {
-    Expr::new_sum(self.into(), rhs)
-  }
+    type Output = Expr;
+    fn add(self, rhs: Expr) -> Expr {
+        Expr::new_sum(self.into(), rhs)
+    }
 }
 
 impl ops::Add<Scalar> for Unknown {
-  type Output = Expr;
-  fn add(self, rhs: Scalar) -> Expr {
-    Expr::new_sum(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn add(self, rhs: Scalar) -> Expr {
+        Expr::new_sum(self.into(), rhs.into())
+    }
 }
 
 impl ops::Add<Unknown> for Unknown {
-  type Output = Expr;
-  fn add(self, rhs: Unknown) -> Expr {
-    Expr::new_sum(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn add(self, rhs: Unknown) -> Expr {
+        Expr::new_sum(self.into(), rhs.into())
+    }
 }
 
 impl ops::Sub<Expr> for Unknown {
-  type Output = Expr;
-  fn sub(self, rhs: Expr) -> Expr {
-    Expr::new_minus(self.into(), rhs)
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Expr) -> Expr {
+        Expr::new_minus(self.into(), rhs)
+    }
 }
 
 impl ops::Sub<Scalar> for Unknown {
-  type Output = Expr;
-  fn sub(self, rhs: Scalar) -> Expr {
-    Expr::new_minus(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Scalar) -> Expr {
+        Expr::new_minus(self.into(), rhs.into())
+    }
 }
 
 impl ops::Sub<Unknown> for Unknown {
-  type Output = Expr;
-  fn sub(self, rhs: Unknown) -> Expr {
-    Expr::new_minus(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn sub(self, rhs: Unknown) -> Expr {
+        Expr::new_minus(self.into(), rhs.into())
+    }
 }
 
 impl ops::Mul<Expr> for Unknown {
-  type Output = Expr;
-  fn mul(self, rhs: Expr) -> Expr {
-    Expr::new_product(self.into(), rhs)
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Expr) -> Expr {
+        Expr::new_product(self.into(), rhs)
+    }
 }
 
 impl ops::Mul<Scalar> for Unknown {
-  type Output = Expr;
-  fn mul(self, rhs: Scalar) -> Expr {
-    Expr::new_product(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Scalar) -> Expr {
+        Expr::new_product(self.into(), rhs.into())
+    }
 }
 
 impl ops::Mul<Unknown> for Unknown {
-  type Output = Expr;
-  fn mul(self, rhs: Unknown) -> Expr {
-    Expr::new_product(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn mul(self, rhs: Unknown) -> Expr {
+        Expr::new_product(self.into(), rhs.into())
+    }
 }
 
 impl ops::Div<Expr> for Unknown {
-  type Output = Expr;
-  fn div(self, rhs: Expr) -> Expr {
-    Expr::new_div(self.into(), rhs)
-  }
+    type Output = Expr;
+    fn div(self, rhs: Expr) -> Expr {
+        Expr::new_div(self.into(), rhs)
+    }
 }
 
 impl ops::Div<Scalar> for Unknown {
-  type Output = Expr;
-  fn div(self, rhs: Scalar) -> Expr {
-    Expr::new_div(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn div(self, rhs: Scalar) -> Expr {
+        Expr::new_div(self.into(), rhs.into())
+    }
 }
 
 impl ops::Div<Unknown> for Unknown {
-  type Output = Expr;
-  fn div(self, rhs: Unknown) -> Expr {
-    Expr::new_div(self.into(), rhs.into())
-  }
+    type Output = Expr;
+    fn div(self, rhs: Unknown) -> Expr {
+        Expr::new_div(self.into(), rhs.into())
+    }
 }
 
 impl ops::Neg for Unknown {
-  type Output = Expr;
-  fn neg(self) -> Expr {
-    Expr::new_neg(self.into())
-  }
+    type Output = Expr;
+    fn neg(self) -> Expr {
+        Expr::new_neg(self.into())
+    }
 }
diff --git a/src/math/region.rs b/src/math/region.rs
index 09a1cae..00ff31e 100644
--- a/src/math/region.rs
+++ b/src/math/region.rs
@@ -1,6 +1,6 @@
 use std::fmt;
 
-use super::{eqn, Value, Scalar, Expr, Point2, Rot2};
+use super::{eqn, Expr, Point2, Rot2, Scalar, Value};
 
 // pub type Vec2 = nalgebra::Vector2<Value>;
 // pub type Point2 = nalgebra::Point2<Value>;
@@ -39,7 +39,7 @@ impl fmt::Display for Region1 {
             Singleton(v) => write!(f, "{{ {} }}", v),
             Range(l, u) => write!(f, "[ {}, {} ]", l, u),
             Intersection(r1, r2) => write!(f, "{} ∩ {}", r1, r2),
-            Full => write!(f, "ℝ")
+            Full => write!(f, "ℝ"),
         }
     }
 }
@@ -119,23 +119,20 @@ impl Region<Scalar> for Region1 {
                 },
                 _ => None,
             },
-            Intersection(r1, r2) => {
-                unimplemented!()
-            }
-            /*Union(r1, r2) => {
-                let distance = |a: Scalar, b: Scalar| (a - b).abs();
-                match (r1.nearest(s), r2.nearest(s)) {
-                    (None, None) => None,
-                    (Some(n), None) | (None, Some(n)) => Some(n),
-                    (Some(n1), Some(n2)) => Some({
-                        if distance(*s, n1) <= distance(*s, n2) {
-                            n1
-                        } else {
-                            n2
-                        }
-                    }),
-                }
-            }*/
+            Intersection(r1, r2) => unimplemented!(), /*Union(r1, r2) => {
+                                                          let distance = |a: Scalar, b: Scalar| (a - b).abs();
+                                                          match (r1.nearest(s), r2.nearest(s)) {
+                                                              (None, None) => None,
+                                                              (Some(n), None) | (None, Some(n)) => Some(n),
+                                                              (Some(n1), Some(n2)) => Some({
+                                                                  if distance(*s, n1) <= distance(*s, n2) {
+                                                                      n1
+                                                                  } else {
+                                                                      n2
+                                                                  }
+                                                              }),
+                                                          }
+                                                      }*/
         }
     }
 }
@@ -151,7 +148,11 @@ pub struct Line2 {
 
 impl fmt::Display for Line2 {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{{ <x, y> = {} + {} * {} }}", self.start, self.dir, self.extent)
+        write!(
+            f,
+            "{{ <x, y> = {} + {} * {} }}",
+            self.start, self.dir, self.extent
+        )
     }
 }
 
@@ -170,9 +171,13 @@ impl Line2 {
             _ => None,
         }
     }
-    
+
     pub fn with_extent(self, new_extent: Region1) -> Line2 {
-        Line2 { start: self.start, dir: self.dir, extent: new_extent }
+        Line2 {
+            start: self.start,
+            dir: self.dir,
+            extent: new_extent,
+        }
     }
 
     pub fn nearest(&self, p: &Point2<Value>) -> Point2<Value> {
@@ -182,7 +187,7 @@ impl Line2 {
         match self.intersect(&perp) {
             Region2::Singleton(np) => np,
             Region2::Line(l) => l.evaluate_extent().expect("Line2::nearest not found"),
-            _ => panic!("Line2::nearest not found!")
+            _ => panic!("Line2::nearest not found!"),
         }
     }
 
@@ -208,7 +213,8 @@ impl Line2 {
             b.dir.clone(),
         );
         let (a_c, a_s, b_c, b_s) = (a_v.cos(), a_v.sin(), b_v.cos(), b_v.sin());
-        let t_b = (a_0.x.clone() * a_s.clone() - a_0.y.clone() * a_c.clone()
+        let t_b = (a_0.x.clone() * a_s.clone()
+            - a_0.y.clone() * a_c.clone()
             - b_0.x.clone() * a_s.clone()
             + b_0.y.clone() * a_c.clone())
             / (a_s.clone() * b_c.clone() - a_c.clone() * b_s.clone());
@@ -225,7 +231,11 @@ impl Line2 {
             dir: self.dir,
             extent: self.extent.simplify(),
         };
-        trace!("line {}: simplify evaluate extent: {:?}", new_l, new_l.evaluate_extent());
+        trace!(
+            "line {}: simplify evaluate extent: {:?}",
+            new_l,
+            new_l.evaluate_extent()
+        );
         if let Some(p) = new_l.evaluate_extent() {
             return Region2::Singleton(p.simplify());
         }
@@ -261,7 +271,7 @@ impl fmt::Display for Region2 {
             Singleton(v) => write!(f, "{{ {} }}", v),
             Line(l) => l.fmt(f),
             Intersection(r1, r2) => write!(f, "{} ∩ {}", r1, r2),
-            Full => write!(f, "ℝ²")
+            Full => write!(f, "ℝ²"),
         }
     }
 }
@@ -328,12 +338,11 @@ impl Region<Point2<Scalar>> for Region2 {
                     (Const(cx), Const(cy)) => Some(Point2::new(cx, cy)),
                     _ => None,
                 }
-            } 
+            }
             Intersection(r1, r2) => {
                 None
                 // r1.clone().intersect((**r2).clone()).nearest(p)
-            }
-            /*Union(r1, r2) => {
+            } /*Union(r1, r2) => {
                   use nalgebra::distance;
                   match (r1.nearest(p), r2.nearest(p)) {
                       (None, None) => None,
@@ -357,7 +366,8 @@ impl Region<Point2<Value>> for Region2 {
     }
 
     fn contains(&self, p: &Point2<Value>) -> Option<bool> {
-        self.nearest(p).map(|n| n.simplify() == p.clone().simplify())
+        self.nearest(p)
+            .map(|n| n.simplify() == p.clone().simplify())
     }
 
     fn nearest(&self, p: &Point2<Value>) -> Option<Point2<Value>> {
@@ -367,23 +377,20 @@ impl Region<Point2<Value>> for Region2 {
             Full => Some(p.clone()),
             Singleton(n) => Some(n.clone()),
             Line(line) => Some(line.nearest(p)),
-            Intersection(r1, r2) => {
-                r1.clone().intersect((**r2).clone()).nearest(p)
-            }
-            /*Union(r1, r2) => {
-                use nalgebra::distance;
-                match (r1.nearest(p), r2.nearest(p)) {
-                    (None, None) => None,
-                    (Some(n), None) | (None, Some(n)) => Some(n),
-                    (Some(n1), Some(n2)) => Some({
-                        if distance(p, &n1) <= distance(p, &n2) {
-                            n1
-                        } else {
-                            n2
-                        }
-                    }),
-                }
-            }*/
+            Intersection(r1, r2) => r1.clone().intersect((**r2).clone()).nearest(p), /*Union(r1, r2) => {
+                                                                                         use nalgebra::distance;
+                                                                                         match (r1.nearest(p), r2.nearest(p)) {
+                                                                                             (None, None) => None,
+                                                                                             (Some(n), None) | (None, Some(n)) => Some(n),
+                                                                                             (Some(n1), Some(n2)) => Some({
+                                                                                                 if distance(p, &n1) <= distance(p, &n2) {
+                                                                                                     n1
+                                                                                                 } else {
+                                                                                                     n2
+                                                                                                 }
+                                                                                             }),
+                                                                                         }
+                                                                                     }*/
         }
     }
 }
@@ -419,9 +426,7 @@ impl Region2 {
                     Region2::intersection(Singleton(n), o)
                 }
             }
-            (Intersection(r1, r2), o) | (o, Intersection(r1, r2)) => {
-                r1.intersect(*r2).intersect(o)
-            }
+            (Intersection(r1, r2), o) | (o, Intersection(r1, r2)) => r1.intersect(*r2).intersect(o),
             (Line(l1), Line(l2)) => l1.intersect(&l2).simplify(),
             /*(Union(un1, un2), o) | (o, Union(un1, un2)) => {
                 Self::union(un1.intersect(o), un2.intersect(o))
@@ -429,4 +434,4 @@ impl Region2 {
             (r1, r2) => Intersection(Box::new(r1), Box::new(r2)),
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/math/unknown.rs b/src/math/unknown.rs
index 55a5f92..c741771 100644
--- a/src/math/unknown.rs
+++ b/src/math/unknown.rs
@@ -1,6 +1,6 @@
 use std::collections::BTreeSet;
-use std::iter::FromIterator;
 use std::fmt;
+use std::iter::FromIterator;
 
 use super::Scalar;
 
@@ -44,4 +44,4 @@ impl fmt::Display for Unknown {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "u{}", self.0)
     }
-}
\ No newline at end of file
+}
diff --git a/src/math/vec.rs b/src/math/vec.rs
index 71c9f96..e5cc6d2 100644
--- a/src/math/vec.rs
+++ b/src/math/vec.rs
@@ -1,300 +1,303 @@
-use super::{Scalar, Value};
 use super::eqn::Eqns;
+use super::{Scalar, Value};
 
 use std::ops;
 
 #[derive(Clone, PartialEq, Debug)]
 pub struct Vec2<T> {
-  pub x: T,
-  pub y: T,
+    pub x: T,
+    pub y: T,
 }
 
 impl<T> Vec2<T> {
-  pub fn new(x: T, y: T) -> Self {
-    Self { x, y }
-  }
+    pub fn new(x: T, y: T) -> Self {
+        Self { x, y }
+    }
 }
 
 impl Vec2<Scalar> {
-  pub fn normal2(self) -> Scalar {
-    self.x * self.x + self.y * self.y
-  }
+    pub fn normal2(self) -> Scalar {
+        self.x * self.x + self.y * self.y
+    }
 
-  pub fn normal(self) -> Scalar {
-    self.normal2().sqrt()
-  }
+    pub fn normal(self) -> Scalar {
+        self.normal2().sqrt()
+    }
 
-  pub fn normalize(self) -> Vec2<Scalar> {
-    self.clone() / self.normal()
-  }
+    pub fn normalize(self) -> Vec2<Scalar> {
+        self.clone() / self.normal()
+    }
 }
 
 impl Vec2<Value> {
-  pub fn simplify(self) -> Self {
-    Self {
-      x: self.x.simplify(),
-      y: self.y.simplify(),
+    pub fn simplify(self) -> Self {
+        Self {
+            x: self.x.simplify(),
+            y: self.y.simplify(),
+        }
     }
-  }
 }
 
 impl<T: ops::Add<U>, U> ops::Add<Vec2<U>> for Vec2<T> {
-  type Output = Vec2<T::Output>;
-  fn add(self, rhs: Vec2<U>) -> Self::Output {
-    Self::Output {
-      x: self.x + rhs.x,
-      y: self.y + rhs.y,
+    type Output = Vec2<T::Output>;
+    fn add(self, rhs: Vec2<U>) -> Self::Output {
+        Self::Output {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
     }
-  }
 }
 
 impl<T: ops::Sub<U>, U> ops::Sub<Vec2<U>> for Vec2<T> {
-  type Output = Vec2<T::Output>;
-  fn sub(self, rhs: Vec2<U>) -> Self::Output {
-    Self::Output {
-      x: self.x - rhs.x,
-      y: self.y - rhs.y,
+    type Output = Vec2<T::Output>;
+    fn sub(self, rhs: Vec2<U>) -> Self::Output {
+        Self::Output {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
     }
-  }
 }
 
 impl<T: ops::Mul<U>, U: Clone> ops::Mul<U> for Vec2<T> {
-  type Output = Vec2<T::Output>;
-  fn mul(self, rhs: U) -> Self::Output {
-    Self::Output {
-      x: self.x * rhs.clone(),
-      y: self.y * rhs,
+    type Output = Vec2<T::Output>;
+    fn mul(self, rhs: U) -> Self::Output {
+        Self::Output {
+            x: self.x * rhs.clone(),
+            y: self.y * rhs,
+        }
     }
-  }
 }
 
 impl<T: ops::Div<U>, U: Clone> ops::Div<U> for Vec2<T> {
-  type Output = Vec2<T::Output>;
-  fn div(self, rhs: U) -> Self::Output {
-    Self::Output {
-      x: self.x / rhs.clone(),
-      y: self.y / rhs,
+    type Output = Vec2<T::Output>;
+    fn div(self, rhs: U) -> Self::Output {
+        Self::Output {
+            x: self.x / rhs.clone(),
+            y: self.y / rhs,
+        }
     }
-  }
 }
 
 #[derive(Clone, PartialEq, Debug)]
 pub struct Point2<T> {
-  pub x: T,
-  pub y: T,
+    pub x: T,
+    pub y: T,
 }
 
 impl<T> Point2<T> {
-  pub fn new(x: T, y: T) -> Point2<T> {
-    Point2 { x, y }
-  }
+    pub fn new(x: T, y: T) -> Point2<T> {
+        Point2 { x, y }
+    }
 }
 
 impl Point2<Value> {
-  pub fn simplify(self) -> Self {
-    Self {
-      x: self.x.distribute().simplify(),
-      y: self.y.distribute().simplify(),
+    pub fn simplify(self) -> Self {
+        Self {
+            x: self.x.distribute().simplify(),
+            y: self.y.distribute().simplify(),
+        }
     }
-  }
 
-  pub fn evaluate_with(self, eqns: &Eqns) -> Self {
-    Self {
-      x: self.x.evaluate_with(eqns),
-      y: self.y.evaluate_with(eqns),
+    pub fn evaluate_with(self, eqns: &Eqns) -> Self {
+        Self {
+            x: self.x.evaluate_with(eqns),
+            y: self.y.evaluate_with(eqns),
+        }
     }
-  }
 }
 
 impl From<Point2<Scalar>> for Point2<Value> {
-  fn from(sp: Point2<Scalar>) -> Self {
-    Self { x: sp.x.into(), y: sp.y.into() }
-  }
+    fn from(sp: Point2<Scalar>) -> Self {
+        Self {
+            x: sp.x.into(),
+            y: sp.y.into(),
+        }
+    }
 }
 
 impl<T: ops::Add<U>, U> ops::Add<Vec2<U>> for Point2<T> {
-  type Output = Point2<T::Output>;
-  fn add(self, rhs: Vec2<U>) -> Self::Output {
-    Point2 {
-      x: self.x + rhs.x,
-      y: self.y + rhs.y,
+    type Output = Point2<T::Output>;
+    fn add(self, rhs: Vec2<U>) -> Self::Output {
+        Point2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
     }
-  }
 }
 
 impl<T: ops::Sub<U>, U> ops::Sub<Vec2<U>> for Point2<T> {
-  type Output = Point2<T::Output>;
-  fn sub(self, rhs: Vec2<U>) -> Self::Output {
-    Point2 {
-      x: self.x - rhs.x,
-      y: self.y - rhs.y,
+    type Output = Point2<T::Output>;
+    fn sub(self, rhs: Vec2<U>) -> Self::Output {
+        Point2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
     }
-  }
 }
 
 impl<T: ops::Sub<U>, U> ops::Sub<Point2<U>> for Point2<T> {
-  type Output = Vec2<T::Output>;
-  fn sub(self, rhs: Point2<U>) -> Self::Output {
-    Vec2 {
-      x: self.x - rhs.x,
-      y: self.y - rhs.y,
+    type Output = Vec2<T::Output>;
+    fn sub(self, rhs: Point2<U>) -> Self::Output {
+        Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
     }
-  }
 }
 
 use std::fmt;
 
 impl<T: fmt::Display> fmt::Display for Point2<T> {
-  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "<{}, {}>", self.x, self.y)
-  }
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "<{}, {}>", self.x, self.y)
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Debug)]
 pub struct Rot2 {
-  cos: Scalar,
-  sin: Scalar,
+    cos: Scalar,
+    sin: Scalar,
 }
 
 impl fmt::Display for Rot2 {
-  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "<{}, {}>", self.cos, self.sin)
-  }
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "<{}, {}>", self.cos, self.sin)
+    }
 }
 
 impl Rot2 {
-  pub fn from_cos_sin_unchecked(cos: Scalar, sin: Scalar) -> Self {
-    Self { cos, sin }
-  }
-
-  pub fn up() -> Self {
-    Self { cos: 0., sin: 1. }
-  }
-
-  pub fn right() -> Self {
-    Self { cos: 1., sin: 0. }
-  }
-
-  pub fn from_cos_sin(cos: Scalar, sin: Scalar) -> Self {
-    Vec2 { x: cos, y: sin }.into()
-  }
-
-  pub fn from_angle(angle: Scalar) -> Self {
-    Self {
-      cos: angle.cos().into(),
-      sin: angle.sin().into(),
-    }
-  }
-
-  pub fn from_angle_deg(angle_deg: Scalar) -> Self {
-    Self::from_angle(angle_deg * std::f64::consts::PI / 180.)
-  }
-
-  pub fn cardinal(index: i64) -> Self {
-    match index % 4 {
-      0 => Rot2 {
-        cos: (1.).into(),
-        sin: (0.).into(),
-      },
-      1 => Rot2 {
-        cos: (0.).into(),
-        sin: (1.).into(),
-      },
-      2 => Rot2 {
-        cos: (-1.).into(),
-        sin: (0.).into(),
-      },
-      3 => Rot2 {
-        cos: (0.).into(),
-        sin: (-1.).into(),
-      },
-      _ => unreachable!(),
-    }
-  }
-
-  pub fn cos(&self) -> Scalar {
-    self.cos
-  }
-
-  pub fn sin(&self) -> Scalar {
-    self.sin
-  }
-
-  pub fn conj(self) -> Self {
-    Self {
-      cos: self.cos,
-      sin: -self.sin,
-    }
-  }
-
-  pub fn dot(self, v: Vec2<Value>) -> Value {
-    v.x * self.cos + v.y * self.sin
-  }
+    pub fn from_cos_sin_unchecked(cos: Scalar, sin: Scalar) -> Self {
+        Self { cos, sin }
+    }
+
+    pub fn up() -> Self {
+        Self { cos: 0., sin: 1. }
+    }
+
+    pub fn right() -> Self {
+        Self { cos: 1., sin: 0. }
+    }
+
+    pub fn from_cos_sin(cos: Scalar, sin: Scalar) -> Self {
+        Vec2 { x: cos, y: sin }.into()
+    }
+
+    pub fn from_angle(angle: Scalar) -> Self {
+        Self {
+            cos: angle.cos().into(),
+            sin: angle.sin().into(),
+        }
+    }
+
+    pub fn from_angle_deg(angle_deg: Scalar) -> Self {
+        Self::from_angle(angle_deg * std::f64::consts::PI / 180.)
+    }
+
+    pub fn cardinal(index: i64) -> Self {
+        match index % 4 {
+            0 => Rot2 {
+                cos: (1.).into(),
+                sin: (0.).into(),
+            },
+            1 => Rot2 {
+                cos: (0.).into(),
+                sin: (1.).into(),
+            },
+            2 => Rot2 {
+                cos: (-1.).into(),
+                sin: (0.).into(),
+            },
+            3 => Rot2 {
+                cos: (0.).into(),
+                sin: (-1.).into(),
+            },
+            _ => unreachable!(),
+        }
+    }
+
+    pub fn cos(&self) -> Scalar {
+        self.cos
+    }
+
+    pub fn sin(&self) -> Scalar {
+        self.sin
+    }
+
+    pub fn conj(self) -> Self {
+        Self {
+            cos: self.cos,
+            sin: -self.sin,
+        }
+    }
+
+    pub fn dot(self, v: Vec2<Value>) -> Value {
+        v.x * self.cos + v.y * self.sin
+    }
 }
 
 impl From<Vec2<Scalar>> for Rot2 {
-  fn from(v: Vec2<Scalar>) -> Rot2 {
-    let v = v.normalize();
-    Rot2 { cos: v.x, sin: v.y }
-  }
+    fn from(v: Vec2<Scalar>) -> Rot2 {
+        let v = v.normalize();
+        Rot2 { cos: v.x, sin: v.y }
+    }
 }
 
 impl ops::Mul<Scalar> for Rot2 {
-  type Output = Vec2<Scalar>;
-  fn mul(self, rhs: Scalar) -> Vec2<Scalar> {
-    Vec2 {
-      x: self.cos * rhs,
-      y: self.sin * rhs,
+    type Output = Vec2<Scalar>;
+    fn mul(self, rhs: Scalar) -> Vec2<Scalar> {
+        Vec2 {
+            x: self.cos * rhs,
+            y: self.sin * rhs,
+        }
     }
-  }
 }
 
 impl ops::Mul<Value> for Rot2 {
-  type Output = Vec2<Value>;
-  fn mul(self, rhs: Value) -> Vec2<Value> {
-    Vec2 {
-      x: rhs.clone() * self.cos,
-      y: rhs * self.sin,
+    type Output = Vec2<Value>;
+    fn mul(self, rhs: Value) -> Vec2<Value> {
+        Vec2 {
+            x: rhs.clone() * self.cos,
+            y: rhs * self.sin,
+        }
     }
-  }
 }
 
 impl ops::Add<Rot2> for Rot2 {
-  type Output = Rot2;
-  fn add(self, rhs: Rot2) -> Rot2 {
-    Rot2 {
-      cos: self.cos.clone() * rhs.cos.clone() - self.sin.clone() * rhs.sin.clone(),
-      sin: self.cos * rhs.sin + self.sin * rhs.cos,
+    type Output = Rot2;
+    fn add(self, rhs: Rot2) -> Rot2 {
+        Rot2 {
+            cos: self.cos.clone() * rhs.cos.clone() - self.sin.clone() * rhs.sin.clone(),
+            sin: self.cos * rhs.sin + self.sin * rhs.cos,
+        }
     }
-  }
 }
 
 impl ops::Sub<Rot2> for Rot2 {
-  type Output = Rot2;
-  fn sub(self, rhs: Rot2) -> Rot2 {
-    Rot2 {
-      cos: self.cos.clone() * rhs.cos.clone() + self.sin.clone() * rhs.sin.clone(),
-      sin: self.sin * rhs.cos - self.cos * rhs.sin,
+    type Output = Rot2;
+    fn sub(self, rhs: Rot2) -> Rot2 {
+        Rot2 {
+            cos: self.cos.clone() * rhs.cos.clone() + self.sin.clone() * rhs.sin.clone(),
+            sin: self.sin * rhs.cos - self.cos * rhs.sin,
+        }
     }
-  }
 }
 
 impl ops::Mul<Vec2<Scalar>> for Rot2 {
-  type Output = Vec2<Scalar>;
-  fn mul(self, rhs: Vec2<Scalar>) -> Vec2<Scalar> {
-    Vec2 {
-      x: self.cos * rhs.x - self.sin * rhs.y,
-      y: self.cos * rhs.y + self.sin * rhs.x,
+    type Output = Vec2<Scalar>;
+    fn mul(self, rhs: Vec2<Scalar>) -> Vec2<Scalar> {
+        Vec2 {
+            x: self.cos * rhs.x - self.sin * rhs.y,
+            y: self.cos * rhs.y + self.sin * rhs.x,
+        }
     }
-  }
 }
 
 impl ops::Mul<Vec2<Value>> for Rot2 {
-  type Output = Vec2<Value>;
-  fn mul(self, rhs: Vec2<Value>) -> Vec2<Value> {
-    Vec2 {
-      x: rhs.x.clone() * self.cos - rhs.y.clone() * self.sin,
-      y: rhs.y * self.cos + rhs.x * self.sin,
+    type Output = Vec2<Value>;
+    fn mul(self, rhs: Vec2<Value>) -> Vec2<Value> {
+        Vec2 {
+            x: rhs.x.clone() * self.cos - rhs.y.clone() * self.sin,
+            y: rhs.y * self.cos + rhs.x * self.sin,
+        }
     }
-  }
 }
diff --git a/src/relation.rs b/src/relation.rs
index 79de1e0..032167e 100644
--- a/src/relation.rs
+++ b/src/relation.rs
@@ -1,5 +1,5 @@
 use crate::entity::{CPoint as PointEntity, PointRef};
-use crate::math::{Line2, Vec2, Point2, Region1, Region2, Rot2, Scalar, Value, GenericRegion};
+use crate::math::{GenericRegion, Line2, Point2, Region1, Region2, Rot2, Scalar, Value, Vec2};
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum ResolveResult {
@@ -31,7 +31,12 @@ pub struct Coincident {
 impl Relation for Coincident {
     fn resolve(&self) -> ResolveResult {
         let (mut p1, mut p2) = (self.p1.borrow_mut(), self.p2.borrow_mut());
-        let r = { p1.constraints().clone().intersect(p2.constraints().clone()).simplify() };
+        let r = {
+            p1.constraints()
+                .clone()
+                .intersect(p2.constraints().clone())
+                .simplify()
+        };
         p1.reconstrain(r.clone());
         p2.reconstrain(r.clone());
         ResolveResult::from_r2(&r)
@@ -50,11 +55,19 @@ impl PointAngle {
     }
 
     pub fn new_horizontal(p1: PointRef, p2: PointRef) -> Self {
-        Self::new(p1, p2, Rot2::from_cos_sin_unchecked((1.).into(), (0.).into()))
+        Self::new(
+            p1,
+            p2,
+            Rot2::from_cos_sin_unchecked((1.).into(), (0.).into()),
+        )
     }
 
     pub fn new_vertical(p1: PointRef, p2: PointRef) -> Self {
-        Self::new(p1, p2, Rot2::from_cos_sin_unchecked((0.).into(), (1.).into()))
+        Self::new(
+            p1,
+            p2,
+            Rot2::from_cos_sin_unchecked((0.).into(), (1.).into()),
+        )
     }
 }
 
@@ -64,7 +77,11 @@ impl Relation for PointAngle {
         let (mut p1, mut p2) = (self.p1.borrow_mut(), self.p2.borrow_mut());
         let constrain_line = |p1: &Point2<Value>, p2: &mut PointEntity| {
             let line = Region2::Line(Line2::new(p1.clone(), self.angle.clone(), Region1::Full));
-            trace!("PointAngle line: {}, p2 constraint: {}", line, p2.constraints());
+            trace!(
+                "PointAngle line: {}, p2 constraint: {}",
+                line,
+                p2.constraints()
+            );
             let new_constraint = p2.constraints().clone().intersection(line).simplify();
             trace!("PointAngle new_constraint: {}", new_constraint);
             p2.reconstrain(new_constraint);
@@ -78,9 +95,9 @@ impl Relation for PointAngle {
                 let r = self.angle.clone().conj() * (p2.clone() - p1.clone());
                 trace!("angle.cos: {}", r.x);
                 // if relative_eq!(r.y, 0.) {
-                    ResolveResult::Constrained
+                ResolveResult::Constrained
                 // } else {
-                    // ResolveResult::Overconstrained
+                // ResolveResult::Overconstrained
                 // }
             }
             (Singleton(p), _) => constrain_line(p, &mut *p2),
@@ -123,7 +140,11 @@ impl Relation for AlignedDistance {
         let constrain_line = |p1: Point2<Value>, p2: &mut PointEntity| {
             let angle = self.angle + Rot2::up();
             let line = Region2::Line(Line2::new(p1.clone(), angle, Region1::Full)).simplify();
-            trace!("AlignedDistance line: {}, p2 constraint: {}", line, p2.constraints());
+            trace!(
+                "AlignedDistance line: {}, p2 constraint: {}",
+                line,
+                p2.constraints()
+            );
             let new_constraint = p2.constraints().clone().intersection(line).simplify();
             trace!("AlignedDistance new_constraint: {}", new_constraint);
             p2.reconstrain(new_constraint);
@@ -136,9 +157,9 @@ impl Relation for AlignedDistance {
                 let r = p2.clone() - p1.clone();
                 let d = self.angle.dot(r);
                 // if relative_eq!(d, self.distance) {
-                    ResolveResult::Constrained
+                ResolveResult::Constrained
                 // } else {
-                    // ResolveResult::Overconstrained
+                // ResolveResult::Overconstrained
                 // }
             }
             (Singleton(pos), _) => constrain_line(pos.clone() + offset, &mut *p2),