diff --git a/app-proto/src/add_remove.rs b/app-proto/src/add_remove.rs
index 3280dac..c96d5ab 100644
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@@ -7,7 +7,6 @@ use crate::{
     assembly::{
         Assembly,
         Regulator,
-        RegulatorRole,
         Element
     },
     engine::Q
@@ -209,14 +208,12 @@ pub fn AddRemove() -> View {
                             reps.0.dot(&(&*Q * reps.1))
                         }
                     );
-                    let set_point = create_signal(0.0);
-                    let role = create_signal(RegulatorRole::Measurement);
+                    let set_point = create_signal(None);
                     state.assembly.insert_regulator(Regulator {
                         subjects: subjects,
                         measurement: measurement,
                         set_point: set_point,
-                        set_point_text: create_signal(String::new()),
-                        role: role,
+                        set_point_spec: create_signal(String::new())
                     });
                     state.selection.update(|sel| sel.clear());
                     
@@ -241,8 +238,7 @@ pub fn AddRemove() -> View {
                         console::log_1(&JsValue::from(
                             format!("Updated constraint with subjects ({}, {})", subjects.0, subjects.1)
                         ));
-                        set_point.track();
-                        if role.with(|rl| rl.is_valid_constraint()) {
+                        if set_point.with(|set_pt| set_pt.is_some()) {
                             state.assembly.realize();
                         }
                     });
diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index c052a3b..c1eba1e 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -111,32 +111,17 @@ impl Element {
     }
 }
 
-pub enum RegulatorRole {
-    Measurement,
-    Constraint(bool)
-}
-
-impl RegulatorRole {
-    pub fn is_valid_constraint(&self) -> bool {
-        match self {
-            RegulatorRole::Measurement => false,
-            RegulatorRole::Constraint(valid) => *valid
-        }
-    }
-}
-
-#[derive(Clone)]
+#[derive(Clone, Copy)]
 pub struct Regulator {
     pub subjects: (ElementKey, ElementKey),
     pub measurement: ReadSignal<f64>,
-    pub set_point: Signal<f64>,
-    pub set_point_text: Signal<String>,
-    pub role: Signal<RegulatorRole>
+    pub set_point: Signal<Option<f64>>,
+    pub set_point_spec: Signal<String>
 }
 
 impl Regulator {
-    fn role_is_valid_constraint_untracked(&self) -> bool {
-        self.role.with_untracked(|role| role.is_valid_constraint())
+    pub fn has_no_set_point_spec(&self) -> bool {
+        self.set_point_spec.with(|spec| spec.is_empty())
     }
 }
 
@@ -250,11 +235,14 @@ impl Assembly {
             let mut gram_to_be = PartialMatrix::new();
             self.regulators.with_untracked(|regs| {
                 for (_, reg) in regs {
-                    if reg.role_is_valid_constraint_untracked() {
-                        let subjects = reg.subjects;
-                        let row = elts[subjects.0].column_index.unwrap();
-                        let col = elts[subjects.1].column_index.unwrap();
-                        gram_to_be.push_sym(row, col, reg.set_point.get_untracked());
+                    match reg.set_point.get_untracked() {
+                        Some(set_pt) => {
+                            let subjects = reg.subjects;
+                            let row = elts[subjects.0].column_index.unwrap();
+                            let col = elts[subjects.1].column_index.unwrap();
+                            gram_to_be.push_sym(row, col, set_pt);
+                        },
+                        None => ()
                     }
                 }
             });
diff --git a/app-proto/src/outline.rs b/app-proto/src/outline.rs
index 8dcda93..d892f0f 100644
--- a/app-proto/src/outline.rs
+++ b/app-proto/src/outline.rs
@@ -1,8 +1,6 @@
 use itertools::Itertools;
 use sycamore::prelude::*;
 use web_sys::{
-    Event,
-    HtmlInputElement,
     KeyboardEvent,
     MouseEvent,
     wasm_bindgen::JsCast
@@ -14,7 +12,6 @@ use crate::{
     assembly::{
         Regulator,
         RegulatorKey,
-        RegulatorRole::*,
         ElementKey
     }
 };
@@ -22,25 +19,17 @@ use crate::{
 // an editable view of a regulator
 #[component(inline_props)]
 fn RegulatorInput(regulator: Regulator) -> View {
+    let value = create_signal(regulator.set_point_spec.get_clone_untracked());
+    create_effect(move || value.set(regulator.set_point_spec.get_clone()));
     view! {
         input(
             r#type="text",
             placeholder=regulator.measurement.with(|result| result.to_string()),
-            bind:value=regulator.set_point_text,
-            on:change=move |event: Event| {
-                let target: HtmlInputElement = event.target().unwrap().unchecked_into();
-                let value = target.value();
-                if value.is_empty() {
-                    regulator.role.set(Measurement);
-                } else {
-                    match target.value().parse::<f64>() {
-                        Ok(set_pt) => batch(|| {
-                            regulator.set_point.set(set_pt);
-                            regulator.role.set(Constraint(true));
-                        }),
-                        Err(_) => regulator.role.set(Constraint(false))
-                    };
-                }
+            bind:value=value,
+            on:change=move |_| {
+                let value_val = value.get_clone_untracked();
+                regulator.set_point.set(value_val.parse::<f64>().ok());
+                regulator.set_point_spec.set(value_val);
             }
         )
     }
@@ -51,20 +40,20 @@ fn RegulatorInput(regulator: Regulator) -> View {
 fn RegulatorOutlineItem(regulator_key: RegulatorKey, element_key: ElementKey) -> View {
     let state = use_context::<AppState>();
     let assembly = &state.assembly;
-    let regulator = assembly.regulators.with(|regs| regs[regulator_key].clone());
+    let regulator = assembly.regulators.with(|regs| regs[regulator_key]);
     let other_subject = if regulator.subjects.0 == element_key {
         regulator.subjects.1
     } else {
         regulator.subjects.0
     };
     let other_subject_label = assembly.elements.with(|elts| elts[other_subject].label.clone());
-    let class = regulator.role.map(
-        |role| match role {
-            Measurement => "regulator",
-            Constraint(true) => "regulator valid-constraint",
-            Constraint(false) => "regulator invalid-constraint"
+    let class = create_memo(move || {
+        match regulator.set_point.get() {
+            None if regulator.has_no_set_point_spec() => "regulator",
+            None => "regulator invalid-constraint",
+            Some(_) => "regulator valid-constraint"
         }
-    );
+    });
     view! {
         li(class=class.get()) {
             div(class="regulator-label") { (other_subject_label) }