diff --git a/app-proto/src/add_remove.rs b/app-proto/src/add_remove.rs
index 92ae4be..6fee142 100644
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@@ -11,7 +11,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("gemini_a"),
             label: String::from("Castor"),
             color: [1.00_f32, 0.25_f32, 0.00_f32],
-            rep: engine::sphere(0.5, 0.5, 0.0, 1.0),
+            representation: engine::sphere(0.5, 0.5, 0.0, 1.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -21,7 +21,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("gemini_b"),
             label: String::from("Pollux"),
             color: [0.00_f32, 0.25_f32, 1.00_f32],
-            rep: engine::sphere(-0.5, -0.5, 0.0, 1.0),
+            representation: engine::sphere(-0.5, -0.5, 0.0, 1.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -31,7 +31,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("ursa_major"),
             label: String::from("Ursa major"),
             color: [0.25_f32, 0.00_f32, 1.00_f32],
-            rep: engine::sphere(-0.5, 0.5, 0.0, 0.75),
+            representation: engine::sphere(-0.5, 0.5, 0.0, 0.75),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -41,7 +41,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("ursa_minor"),
             label: String::from("Ursa minor"),
             color: [0.25_f32, 1.00_f32, 0.00_f32],
-            rep: engine::sphere(0.5, -0.5, 0.0, 0.5),
+            representation: engine::sphere(0.5, -0.5, 0.0, 0.5),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -51,7 +51,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("moon_deimos"),
             label: String::from("Deimos"),
             color: [0.75_f32, 0.75_f32, 0.00_f32],
-            rep: engine::sphere(0.0, 0.15, 1.0, 0.25),
+            representation: engine::sphere(0.0, 0.15, 1.0, 0.25),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -61,7 +61,7 @@ fn load_gen_assemb(assembly: &Assembly) {
             id: String::from("moon_phobos"),
             label: String::from("Phobos"),
             color: [0.00_f32, 0.75_f32, 0.50_f32],
-            rep: engine::sphere(0.0, -0.15, -1.0, 0.25),
+            representation: engine::sphere(0.0, -0.15, -1.0, 0.25),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -76,7 +76,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "central".to_string(),
             label: "Central".to_string(),
             color: [0.75_f32, 0.75_f32, 0.75_f32],
-            rep: engine::sphere(0.0, 0.0, 0.0, 1.0),
+            representation: engine::sphere(0.0, 0.0, 0.0, 1.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -86,7 +86,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "assemb_plane".to_string(),
             label: "Assembly plane".to_string(),
             color: [0.75_f32, 0.75_f32, 0.75_f32],
-            rep: engine::sphere_with_offset(0.0, 0.0, 1.0, 0.0, 0.0),
+            representation: engine::sphere_with_offset(0.0, 0.0, 1.0, 0.0, 0.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -96,7 +96,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "side1".to_string(),
             label: "Side 1".to_string(),
             color: [1.00_f32, 0.00_f32, 0.25_f32],
-            rep: engine::sphere_with_offset(1.0, 0.0, 0.0, 1.0, 0.0),
+            representation: engine::sphere_with_offset(1.0, 0.0, 0.0, 1.0, 0.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -106,7 +106,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "side2".to_string(),
             label: "Side 2".to_string(),
             color: [0.25_f32, 1.00_f32, 0.00_f32],
-            rep: engine::sphere_with_offset(-0.5, a, 0.0, 1.0, 0.0),
+            representation: engine::sphere_with_offset(-0.5, a, 0.0, 1.0, 0.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -116,7 +116,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "side3".to_string(),
             label: "Side 3".to_string(),
             color: [0.00_f32, 0.25_f32, 1.00_f32],
-            rep: engine::sphere_with_offset(-0.5, -a, 0.0, 1.0, 0.0),
+            representation: engine::sphere_with_offset(-0.5, -a, 0.0, 1.0, 0.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -126,7 +126,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "corner1".to_string(),
             label: "Corner 1".to_string(),
             color: [0.75_f32, 0.75_f32, 0.75_f32],
-            rep: engine::sphere(-4.0/3.0, 0.0, 0.0, 1.0/3.0),
+            representation: engine::sphere(-4.0/3.0, 0.0, 0.0, 1.0/3.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -136,7 +136,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: "corner2".to_string(),
             label: "Corner 2".to_string(),
             color: [0.75_f32, 0.75_f32, 0.75_f32],
-            rep: engine::sphere(2.0/3.0, -4.0/3.0 * a, 0.0, 1.0/3.0),
+            representation: engine::sphere(2.0/3.0, -4.0/3.0 * a, 0.0, 1.0/3.0),
             constraints: BTreeSet::default(),
             index: 0
         }
@@ -146,7 +146,7 @@ fn load_low_curv_assemb(assembly: &Assembly) {
             id: String::from("corner3"),
             label: String::from("Corner 3"),
             color: [0.75_f32, 0.75_f32, 0.75_f32],
-            rep: engine::sphere(2.0/3.0, 4.0/3.0 * a, 0.0, 1.0/3.0),
+            representation: engine::sphere(2.0/3.0, 4.0/3.0 * a, 0.0, 1.0/3.0),
             constraints: BTreeSet::default(),
             index: 0
         }
diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index 0970932..27774a1 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -12,7 +12,7 @@ pub struct Element {
     pub id: String,
     pub label: String,
     pub color: [f32; 3],
-    pub rep: DVector<f64>,
+    pub representation: DVector<f64>,
     pub constraints: BTreeSet<usize>,
     
     // internal properties, not reflected in any view
@@ -86,7 +86,7 @@ impl Assembly {
                 id: id,
                 label: format!("Sphere {}", id_num),
                 color: [0.75_f32, 0.75_f32, 0.75_f32],
-                rep: DVector::<f64>::from_column_slice(&[0.0, 0.0, 0.0, 0.5, -0.5]),
+                representation: DVector::<f64>::from_column_slice(&[0.0, 0.0, 0.0, 0.5, -0.5]),
                 constraints: BTreeSet::default(),
                 index: 0
             }
@@ -133,7 +133,7 @@ impl Assembly {
             for (_, elt) in elts {
                 let index = elt.index;
                 gram_to_be.push_sym(index, index, 1.0);
-                guess_to_be.set_column(index, &elt.rep);
+                guess_to_be.set_column(index, &elt.representation);
             }
             
             (gram_to_be, guess_to_be)
@@ -177,7 +177,7 @@ impl Assembly {
             // read out the solution
             self.elements.update(|elts| {
                 for (_, elt) in elts.iter_mut() {
-                    elt.rep.set_column(0, &config.column(elt.index));
+                    elt.representation.set_column(0, &config.column(elt.index));
                 }
             });
         }
diff --git a/app-proto/src/display.rs b/app-proto/src/display.rs
index c32b470..79199ec 100644
--- a/app-proto/src/display.rs
+++ b/app-proto/src/display.rs
@@ -297,7 +297,9 @@ pub fn Display() -> View {
                 // get the assembly
                 let elements = state.assembly.elements.get_clone();
                 let element_iter = (&elements).into_iter();
-                let reps_world: Vec<_> = element_iter.clone().map(|(_, elt)| &assembly_to_world * &elt.rep).collect();
+                let reps_world: Vec<_> = element_iter.clone().map(
+                    |(_, elt)| &assembly_to_world * &elt.representation
+                ).collect();
                 let colors: Vec<_> = element_iter.clone().map(|(key, elt)|
                     if state.selection.with(|sel| sel.contains(&key)) {
                         elt.color.map(|ch| 0.2 + 0.8*ch)
diff --git a/app-proto/src/outline.rs b/app-proto/src/outline.rs
index 8edbe07..9ebf34d 100644
--- a/app-proto/src/outline.rs
+++ b/app-proto/src/outline.rs
@@ -72,7 +72,7 @@ pub fn Outline() -> View {
                         }
                     });
                     let label = elt.label.clone();
-                    let rep_components = elt.rep.iter().map(|u| {
+                    let rep_components = elt.representation.iter().map(|u| {
                         let u_coord = u.to_string().replace("-", "\u{2212}");
                         View::from(div().children(u_coord))
                     }).collect::<Vec<_>>();