diff --git a/app-proto/src/add_remove.rs b/app-proto/src/add_remove.rs
index 7066089..00b63f8 100644
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@@ -214,10 +214,11 @@ pub fn AddRemove() -> View {
                             (arg_vec[0].clone(), arg_vec[1].clone())
                         }
                     );
+                    let active = create_signal(true);
                     state.assembly.insert_constraint(Constraint {
                         args: args,
                         rep: 0.0,
-                        active: create_signal(true)
+                        active: active
                     });
                     state.assembly.realize();
                     state.selection.update(|sel| sel.clear());
@@ -236,6 +237,13 @@ pub fn AddRemove() -> View {
                             );
                         }
                     });
+                    
+                    // make constraint activation trigger a realization update
+                    create_effect(move || {
+                        if active.get() {
+                            state.assembly.realize();
+                        }
+                    });
                 }
             ) { "🔗" }
             select(bind:value=assembly_name) { /* DEBUG */
diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index 228357e..648d0ef 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -97,7 +97,7 @@ impl Assembly {
         self.elements.update(|elts| {
             elts[args.0].constraints.insert(key);
             elts[args.1].constraints.insert(key);
-        })
+        });
     }
     
     // --- realization ---
@@ -116,10 +116,12 @@ impl Assembly {
             let mut gram_to_be = PartialMatrix::new();
             self.constraints.with_untracked(|csts| {
                 for (_, cst) in csts {
-                    let args = cst.args;
-                    let row = elts[args.0].index;
-                    let col = elts[args.1].index;
-                    gram_to_be.push_sym(row, col, cst.rep);
+                    if cst.active.get_untracked() {
+                        let args = cst.args;
+                        let row = elts[args.0].index;
+                        let col = elts[args.1].index;
+                        gram_to_be.push_sym(row, col, cst.rep);
+                    }
                 }
             });