diff --git a/app-proto/Cargo.toml b/app-proto/Cargo.toml
index 04ea271..e5bc05e 100644
--- a/app-proto/Cargo.toml
+++ b/app-proto/Cargo.toml
@@ -26,6 +26,7 @@ console_error_panic_hook = { version = "0.1.7", optional = true }
 version = "0.3.69"
 features = [
   'HtmlCanvasElement',
+  'HtmlInputElement',
   'Performance',
   'WebGl2RenderingContext',
   'WebGlBuffer',
diff --git a/app-proto/main.css b/app-proto/main.css
index bdbacfb..44dc7a1 100644
--- a/app-proto/main.css
+++ b/app-proto/main.css
@@ -93,7 +93,7 @@ details[open]:has(li) .elt-switch::after {
   display: flex;
 }
 
-.elt-rep > div, .cst-rep {
+.elt-rep > div {
   padding: 2px 0px 0px 0px;
   font-size: 10pt;
   text-align: center;
@@ -104,10 +104,17 @@ details[open]:has(li) .elt-switch::after {
   font-style: italic;
 }
 
-.cst > input {
+.cst > input[type=checkbox] {
   margin: 0px 8px 0px 0px;
 }
 
+.cst > input[type=number] {
+  color: #fcfcfc;
+  background-color: inherit;
+  border: 1px solid #555;
+  border-radius: 2px;
+}
+
 /* display */
 
 canvas {
diff --git a/app-proto/src/add_remove.rs b/app-proto/src/add_remove.rs
index 00b63f8..5435418 100644
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@@ -214,11 +214,14 @@ pub fn AddRemove() -> View {
                             (arg_vec[0].clone(), arg_vec[1].clone())
                         }
                     );
+                    let rep = create_signal(0.0);
                     let active = create_signal(true);
                     state.assembly.insert_constraint(Constraint {
                         args: args,
-                        rep: 0.0,
-                        active: active
+                        rep: rep,
+                        rep_text: create_signal(String::new()),
+                        rep_valid: create_signal(false),
+                        active: active,
                     });
                     state.assembly.realize();
                     state.selection.update(|sel| sel.clear());
@@ -233,13 +236,19 @@ pub fn AddRemove() -> View {
                                 &JsValue::from(cst.args.0),
                                 &JsValue::from(cst.args.1),
                                 &JsValue::from(":"),
-                                &JsValue::from(cst.rep)
+                                &JsValue::from(cst.rep.get_untracked())
                             );
                         }
                     });
                     
-                    // make constraint activation trigger a realization update
+                    // update the realization when the constraint activated, or
+                    // edited while active
                     create_effect(move || {
+                        rep.track();
+                        console::log_2(
+                            &JsValue::from("Constraint rep updated to"),
+                            &JsValue::from(rep.get_untracked())
+                        );
                         if active.get() {
                             state.assembly.realize();
                         }
diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index 648d0ef..62f5405 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -22,7 +22,9 @@ pub struct Element {
 #[derive(Clone)]
 pub struct Constraint {
     pub args: (usize, usize),
-    pub rep: f64,
+    pub rep: Signal<f64>,
+    pub rep_text: Signal<String>,
+    pub rep_valid: Signal<bool>,
     pub active: Signal<bool>
 }
 
@@ -116,11 +118,11 @@ impl Assembly {
             let mut gram_to_be = PartialMatrix::new();
             self.constraints.with_untracked(|csts| {
                 for (_, cst) in csts {
-                    if cst.active.get_untracked() {
+                    if cst.active.get_untracked() && cst.rep_valid.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);
+                        gram_to_be.push_sym(row, col, cst.rep.get_untracked());
                     }
                 }
             });
diff --git a/app-proto/src/outline.rs b/app-proto/src/outline.rs
index 4e4de9c..d6b0390 100644
--- a/app-proto/src/outline.rs
+++ b/app-proto/src/outline.rs
@@ -1,6 +1,7 @@
 use itertools::Itertools;
 use sycamore::{prelude::*, web::tags::div};
-use web_sys::{Element, KeyboardEvent, MouseEvent, wasm_bindgen::JsCast};
+use web_sys::{Element, Event, HtmlInputElement, KeyboardEvent, MouseEvent, wasm_bindgen::JsCast};
+use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
 
 use crate::AppState;
 
@@ -51,8 +52,6 @@ pub fn Outline() -> View {
                     let constrained = elt.constraints.len() > 0;
                     let details_node = create_node_ref();
                     view! {
-                        /* [TO DO] switch to integer-valued parameters whenever
-                        that becomes possible again */
                         li {
                             details(ref=details_node) {
                                 summary(
@@ -138,7 +137,25 @@ pub fn Outline() -> View {
                                                 li(class="cst") {
                                                     input(r#type="checkbox", bind:checked=cst.active)
                                                     div(class="cst-label") { (other_arg_label) }
-                                                    div(class="cst-rep") { (cst.rep) }
+                                                    input(
+                                                        r#type="number",
+                                                        step="0.01",
+                                                        bind:value=cst.rep_text,
+                                                        on:change=move |event: Event| {
+                                                            let target: HtmlInputElement = event.target().unwrap().unchecked_into();
+                                                            let rep_valid = target.check_validity() && !target.value().is_empty();
+                                                            batch(|| {
+                                                                cst.rep_valid.set(rep_valid);
+                                                                if rep_valid {
+                                                                    console::log_2(
+                                                                        &JsValue::from("Constraint rep parsed to"),
+                                                                        &JsValue::from(target.value_as_number())
+                                                                    );
+                                                                    cst.rep.set(target.value_as_number());
+                                                                }
+                                                            });
+                                                        }
+                                                    )
                                                 }
                                             }
                                         },