diff --git a/src/haz3lcore/statics/MakeTerm.re b/src/haz3lcore/statics/MakeTerm.re
index 38c00f5951..85e5b069c6 100644
--- a/src/haz3lcore/statics/MakeTerm.re
+++ b/src/haz3lcore/statics/MakeTerm.re
@@ -123,16 +123,9 @@ let return = (wrap, ids, tm) => {
 let projectors: ref(Id.Map.t(Piece.projector)) = ref(Id.Map.empty);
 
 /* Strip a projector from a segment and log it in the map */
-let log_projectors = (seg: Segment.t): Segment.t =>
-  List.map(
-    fun
-    | Piece.Projector(pr) => {
-        projectors := Id.Map.add(pr.id, pr, projectors^);
-        Piece.Projector(pr);
-      }
-    | x => x,
-    seg,
-  );
+let log_projector = (pr: Base.projector): unit => {
+  projectors := Id.Map.add(pr.id, pr, projectors^);
+};
 
 let parse_sum_term: UTyp.t => ConstructorMap.variant(UTyp.t) =
   fun
@@ -367,7 +360,7 @@ and pat_term: unsorted => (UPat.term, list(Id.t)) = {
         | ([t], []) when t != " " && !Form.is_explicit_hole(t) =>
           Invalid(t)
         | (["(", ")"], [Pat(body)]) => Parens(body)
-        | (label, [Pat(body)]) when is_probe_wrap(label) => Parens(body)
+        | (label, [Pat(body)]) when is_probe_wrap(label) => body.term
         | (["[", "]"], [Pat(body)]) =>
           switch (body) {
           | {term: Tuple(ps), _} => ListLit(ps)
@@ -428,7 +421,7 @@ and typ_term: unsorted => (UTyp.term, list(Id.t)) = {
         | (["String"], []) => String
         | ([t], []) when Form.is_typ_var(t) => Var(t)
         | (["(", ")"], [Typ(body)]) => Parens(body)
-        | (label, [Typ(body)]) when is_probe_wrap(label) => Parens(body)
+        | (label, [Typ(body)]) when is_probe_wrap(label) => body.term
         | (["[", "]"], [Typ(body)]) => List(body)
         | ([t], []) when t != " " && !Form.is_explicit_hole(t) =>
           Unknown(Hole(Invalid(t)))
@@ -538,12 +531,12 @@ and rul = (unsorted: unsorted): Rul.t => {
 and unsorted = (skel: Skel.t, seg: Segment.t): unsorted => {
   /* Remove projectors. We do this here as opposed to removing
    * them in an external call to save a whole-syntax pass. */
-  let _ = log_projectors(seg);
   let tile_kids = (p: Piece.t): list(Term.Any.t) =>
     switch (p) {
     | Secondary(_)
     | Grout(_) => []
-    | Projector({syntax, id: _, _}) =>
+    | Projector({syntax, id: _, _} as pr) =>
+      let _ = log_projector(pr);
       let sort = Piece.sort(syntax) |> fst;
       [go_s(sort, Segment.skel([syntax]), [syntax])];
     | Tile({mold, shards, children, _}) =>
diff --git a/src/haz3lcore/statics/Statics.re b/src/haz3lcore/statics/Statics.re
index f20e3f8e57..9d9abde74b 100644
--- a/src/haz3lcore/statics/Statics.re
+++ b/src/haz3lcore/statics/Statics.re
@@ -26,7 +26,7 @@
    itself is dedicated to the piping necessary to (A) introduce and
    (B) propagate the necessary information through the syntax tree.
 
-     */
+    */
 
 module Info = Info;
 
diff --git a/src/haz3lcore/tiles/Piece.re b/src/haz3lcore/tiles/Piece.re
index 96b02e1004..fc6207a979 100644
--- a/src/haz3lcore/tiles/Piece.re
+++ b/src/haz3lcore/tiles/Piece.re
@@ -186,13 +186,3 @@ let is_term = (p: t) =>
   | Secondary(_) => false // debatable
   | _ => false
   };
-
-let mk_tile_id: (Id.t, Form.t, list(list(t))) => t =
-  (id, form, children) =>
-    Tile({
-      id,
-      label: form.label,
-      mold: form.mold,
-      shards: List.mapi((i, _) => i, form.label),
-      children,
-    });
diff --git a/src/haz3lcore/zipper/projectors/ProbeProj.re b/src/haz3lcore/zipper/projectors/ProbeProj.re
index e846755dfb..0ce589301d 100644
--- a/src/haz3lcore/zipper/projectors/ProbeProj.re
+++ b/src/haz3lcore/zipper/projectors/ProbeProj.re
@@ -4,25 +4,6 @@ open Virtual_dom.Vdom;
 open Node;
 open Js_of_ocaml;
 
-//let _ = Zipper.base_point; //not cyclical
-//let _ = Editor.show; //cyclical
-
-/* Plan for extended dynamics:
-   in principle we could track:
-   - prev 'stack frame': id of prev expr that began execution?
-   - env (or just the part of the env that's relevant to the current expr)
-     aka the co-ctx
-
-    */
-
-/* Plan for selectable (editable as well maybe):
-
-   selectable:
-   create own mini version of editor, use it as model
-   update fn updates model after applying mini editor action
-   hopefully can use same actions
-    */
-
 [@deriving (show({with_path: false}), sexp, yojson)]
 type t = {
   [@default "⋱"]
@@ -96,22 +77,15 @@ let get_goal = (utility: utility, e: Js.t(Dom_html.mouseEvent)) =>
 let resizable_val =
     (~resizable=false, model, utility, local, pi: Dynamics.Probe.Info.t) => {
   let val_pointerdown = (e: Js.t(Dom_html.pointerEvent)) => {
-    // print_endline("pointerdown");
     let target = e##.target |> Js.Opt.get(_, _ => failwith("no target"));
     JsUtil.setPointerCapture(target, e##.pointerId) |> ignore;
     mousedown := Some(target);
-    // if (last_target^ == [target] && !Js.to_bool(e##.shiftKey)) {
-    //   env_cursor := [];
-    //   last_target := [];
-    // } else {
     env_cursor := Probe.env_stack(pi.stack);
     last_target := [target];
-    // };
     Effect.Ignore;
   };
 
   let val_pointerup = (e: Js.t(Dom_html.pointerEvent)) => {
-    // print_endline("pointerup");
     switch (mousedown^) {
     | Some(target) =>
       JsUtil.releasePointerCapture(target, e##.pointerId) |> ignore
@@ -128,10 +102,7 @@ let resizable_val =
       /* Ideally we could just use hasPointerCapture... */
       let goal = get_goal(utility, e);
       local(ChangeLength(goal.col));
-    // print_endline("mousemove: resizing");
-    | _ =>
-      // print_endline("mousemove: not resizing");
-      Effect.Ignore
+    | _ => Effect.Ignore
     };
 
   div(
@@ -145,10 +116,7 @@ let resizable_val =
       Attr.on_pointerup(val_pointerup),
       Attr.on_mousemove(val_mousemove),
     ],
-    [
-      seg_view(utility, model.len, pi.value),
-      //, text(stack(pi.stack))
-    ],
+    [seg_view(utility, model.len, pi.value)],
   );
 };
 
diff --git a/src/haz3lweb/app/explainthis/Example.re b/src/haz3lweb/app/explainthis/Example.re
index 3941063a23..9408167cf6 100644
--- a/src/haz3lweb/app/explainthis/Example.re
+++ b/src/haz3lweb/app/explainthis/Example.re
@@ -22,8 +22,6 @@ let int = n => mk_monotile(Form.mk_atomic(Exp, n));
 let exp = v => mk_monotile(Form.mk_atomic(Exp, v));
 let pat = v => mk_monotile(Form.mk_atomic(Pat, v));
 let mk_parens_exp = mk_tile(Form.get("parens_exp"));
-let mk_probe = (e: list(Piece.t)) =>
-  mk_tile(Form.mk(Form.ii, ["@@", "@@"], Mold.mk_op(Exp, [Exp])), [e]);
 let mk_fun = mk_tile(Form.get("fun_"));
 let mk_fun_ancestor = mk_ancestor(Form.get("fun_"));
 let mk_parens_ancestor = mk_ancestor(Form.get("parens_exp"));
diff --git a/src/haz3lweb/app/inspector/ProjectorPanel.re b/src/haz3lweb/app/inspector/ProjectorPanel.re
index f52e1a4864..271363b4fe 100644
--- a/src/haz3lweb/app/inspector/ProjectorPanel.re
+++ b/src/haz3lweb/app/inspector/ProjectorPanel.re
@@ -5,12 +5,7 @@ open Projector;
 open Util.OptUtil.Syntax;
 open Util.Web;
 
-/* The projector selection panel on the right of the bottom bar */
-let option_view = (_name, n) =>
-  option([
-    //~attrs=n == name ? [Attr.create("selected", "selected")] : [],
-    text(n),
-  ]);
+// The projector selection panel on the right of the bottom bar
 
 /* Decide which projectors are applicable based on the cursor info.
  * This is slightly inside-out as elsewhere it depends on the underlying
@@ -100,74 +95,56 @@ let might_project: Cursor.cursor(Editors.Update.t) => bool =
       }
     };
 
-let currently_selected = editor =>
-  option_view(
-    switch (kind(editor)) {
-    | None => "fold"
-    | Some(k) => ProjectorView.name(k)
-    },
-  );
-
-let currently_selected_str = (editor, _): string =>
-  switch (kind(editor)) {
-  | None => "fold"
-  | Some(k) => ProjectorView.name(k)
-  };
+let lift = (str, strs) => List.cons(str, List.filter((!=)(str), strs));
 
-let currently_selected_str_opt = (editor, _): option(string) =>
-  switch (kind(editor)) {
-  | None => None
-  | Some(k) => Some(ProjectorView.name(k))
+/* The string names of all projectors applicable to the currently
+ * indicated syntax, with the currently applied projection (if any)
+ * lifted to the top of the list */
+let applicable_projector_strings = (cursor: Cursor.cursor(Editors.Update.t)) => {
+  let strs =
+    applicable_projectors(cursor.info) |> List.map(ProjectorView.name);
+  switch (kind(cursor.editor)) {
+  | None => strs
+  | Some(k) => lift(ProjectorView.name(k), strs)
   };
+};
 
-let view = (~inject, cursor: Cursor.cursor(Editors.Update.t)) => {
-  let applicable_projectors = applicable_projectors(cursor.info);
-  let should_show = might_project(cursor) && applicable_projectors != [];
-  //TODO(andrew): cleanup
-  // print_endline("currentrly: " ++ currently_selected_str(cursor.editor, ()));
-  let applicable_projector_strings =
-    (might_project(cursor) ? applicable_projectors : [Fold])
-    |> List.map(ProjectorView.name);
+/* A selection input for contetually applicable projectors */
+let select_view =
+    (
+      ~inject: Action.project => Ui_effect.t(unit),
+      cursor: Cursor.cursor(Editors.Update.t),
+    ) => {
   let applicable_projector_strings =
-    switch (currently_selected_str_opt(cursor.editor, ())) {
-    | None => applicable_projector_strings
-    | Some(guy) =>
-      List.cons(
-        guy,
-        List.filter(x => x != guy, applicable_projector_strings),
-      )
-    };
+    might_project(cursor) ? applicable_projector_strings(cursor) : [];
   let value =
-    switch (kind(cursor.editor)) {
-    | Some(k) => ProjectorView.name(k)
-    | None =>
-      applicable_projector_strings
-      //|> List.map(currently_selected_str(cursor.editor))
-      |> List.hd
+    switch (applicable_projector_strings) {
+    | [] => ""
+    | [hd, ..._] => hd
     };
-  // print_endline("value: " ++ value);
-  let select_view =
-    Node.select(
-      ~attrs=[
-        Attr.on_change((_, name) =>
-          inject(Action.SetIndicated(ProjectorView.of_name(name)))
-        ),
-        Attr.string_property("value", value),
-      ],
-      applicable_projector_strings
-      |> List.map(option_view("garbageTODO(andrew)")),
-      //|> List.map(currently_selected(cursor.editor)),
-    );
-  let toggle_view =
-    toggle_view(
-      ~inject,
-      cursor.info,
-      id(cursor.editor),
-      kind(cursor.editor) != None,
-      might_project(cursor),
-    );
+  Node.select(
+    ~attrs=[
+      Attr.on_change((_, name) =>
+        inject(SetIndicated(ProjectorView.of_name(name)))
+      ),
+      Attr.string_property("value", value),
+    ],
+    applicable_projector_strings |> List.map(n => option([text(n)])),
+  );
+};
+
+let toggle_view = (~inject, cursor: Cursor.cursor(Editors.Update.t)) =>
+  toggle_view(
+    ~inject,
+    cursor.info,
+    id(cursor.editor),
+    kind(cursor.editor) != None,
+    might_project(cursor),
+  );
+
+let view = (~inject, cursor: Cursor.cursor(Editors.Update.t)) => {
   div(
     ~attrs=[Attr.id("projectors")],
-    (should_show ? [select_view] : []) @ [toggle_view],
+    [select_view(~inject, cursor)] @ [toggle_view(~inject, cursor)],
   );
 };
diff --git a/src/haz3lweb/www/style.css b/src/haz3lweb/www/style.css
index d70e70a422..e38e08bfab 100644
--- a/src/haz3lweb/www/style.css
+++ b/src/haz3lweb/www/style.css
@@ -3,11 +3,10 @@
 @import "style/animations.css";
 @import "style/loading.css";
 @import "style/editor.css";
-@import "style/projectors.css";
+@import "style/projectors/base.css";
 @import "style/nut-menu.css";
 @import "style/cursor-inspector.css";
 @import "style/type-display.css";
-@import "style/projectors-panel.css";
 @import "style/explainthis.css";
 @import "style/exercise-mode.css";
 @import "style/cell.css";
diff --git a/src/haz3lweb/www/style/editor.css b/src/haz3lweb/www/style/editor.css
index a01b275992..767fa6196e 100644
--- a/src/haz3lweb/www/style/editor.css
+++ b/src/haz3lweb/www/style/editor.css
@@ -21,7 +21,9 @@
 /* This is a hack to compensating for default linebreak handling
 * preventing a trailing linebreak in code editors from leaving a
 * trailing blank line, as per https://stackoverflow.com/questions/43492826/.
-* The mysterious chracter below is a zero-width space */
+* The mysterious chracter below is a zero-width space, used here
+* to avoid inserting an extraneous whitespace context for inline
+* syntax views, e.g. type views in the cursor inspector */
 .code-text:after {
   content: "​";
 }
diff --git a/src/haz3lweb/www/style/projectors-panel.css b/src/haz3lweb/www/style/projectors-panel.css
deleted file mode 100644
index 77c184bf59..0000000000
--- a/src/haz3lweb/www/style/projectors-panel.css
+++ /dev/null
@@ -1,29 +0,0 @@
-/* PROJECTORS PANEL */
-
-#projectors {
-  display: flex;
-  gap: 0.75em;
-  align-items: center;
-  padding-left: 0.75em;
-  padding-right: 0.75em;
-  white-space: nowrap;
-  border-radius: 1.1em 0 0 0;
-  outline: 0.3px solid var(--BR2);
-}
-
-#projectors img {
-  width: 0.7em;
-}
-
-#projectors option {
-  font-size: 1em;
-}
-
-#projectors .toggle-switch {
-  display: flex;
-  align-items: center;
-}
-
-#projectors .toggle-switch.inactive {
-  opacity: 40%;
-}
diff --git a/src/haz3lweb/www/style/projectors.css b/src/haz3lweb/www/style/projectors.css
deleted file mode 100644
index bfcfa12cee..0000000000
--- a/src/haz3lweb/www/style/projectors.css
+++ /dev/null
@@ -1,310 +0,0 @@
-/* PROJECTORS */
-
-/* Turn off caret when a block projector is focused */
-#caret:has(~ .projectors .projector.block *:focus) {
-  display: none;
-}
-
-/* Default projector styles */
-
-.projector {
-  position: absolute;
-  display: flex;
-  justify-content: center;
-  align-items: center;
-  color: var(--BR2);
-}
-.projector > *:not(svg) {
-  z-index: var(--projector-z);
-}
-.projector > svg {
-  z-index: var(--projector-backing-z);
-  fill: var(--shard_projector);
-}
-.projector.block > svg {
-  stroke-width: 0.5px;
-  stroke: var(--BR2);
-}
-.projector.indicated > svg {
-  fill: var(--shard-caret-exp);
-}
-.projector > svg > path {
-  vector-effect: non-scaling-stroke;
-}
-.projector.block.selected > svg > path {
-  vector-effect: non-scaling-stroke;
-  stroke: var(--Y3);
-}
-.projector.selected > svg,
-.projector.selected.indicated > svg,
-.projector.block.selected.indicated > svg {
-  fill: var(--shard-selected);
-}
-
-/* PROJECTOR: FOLD */
-
-.projector.fold:hover,
-.projector.indicated.fold {
-  color: --var(BLACK);
-}
-.projector.fold {
-  cursor: pointer;
-  font-family: var(--code-font);
-}
-
-.result .projector.fold {
-  cursor: default;
-}
-
-/* PROJECTOR: INFO */
-
-.projector.type .type {
-  color: var(--token-typ);
-}
-.projector.type {
-  cursor: pointer;
-}
-.projector.type .info {
-  display: flex;
-}
-.projector.type:hover {
-  color: var(--BLACK);
-}
-
-/* PROJECTOR: CHECKBOX */
-
-.projector.check input {
-  margin: 0;
-  filter: sepia(1);
-  cursor: pointer;
-  outline: none;
-}
-.projector.check:not(.indicated):not(:hover) > svg {
-  fill: var(--NONE);
-}
-
-/* PROJECTOR: SLIDERS (INT & FLOAT) */
-
-.projector.slider input,
-.projector.sliderf input {
-  margin: 0;
-  filter: sepia(1);
-  cursor: pointer;
-  outline: none;
-  width: 90%;
-}
-.projector.slider:not(.indicated):not(:hover) > svg,
-.projector.sliderf:not(.indicated):not(:hover) > svg {
-  fill: var(--NONE);
-}
-
-/* PROJECTOR: TEXTAREA */
-
-.projector.text {
-  cursor: default;
-}
-
-.projector.text .wrapper {
-  height: 100%;
-  width: 100%;
-  border-radius: 0.1em;
-}
-
-.projector.text.indicated .cols,
-.projector.text:has(textarea:focus) .cols {
-  color: var(--R1);
-}
-
-.projector.text.indicated > svg {
-  fill: var(--textarea-indicated);
-}
-
-.projector.text .cols {
-  height: 100%;
-  margin-left: 2px;
-  margin-right: 2px;
-  display: flex;
-  border-radius: 0 0.1em 0.1em 0.1em;
-  color: var(--SAND);
-  background: repeating-linear-gradient(
-    var(--NONE),
-    var(--NONE) 1.41em,
-    var(--textarea-h-stripe) 1.41em,
-    var(--textarea-h-stripe) 1.47em /* line-height */
-  );
-}
-
-.projector.text.selected .cols {
-  background: repeating-linear-gradient(
-    var(--NONE),
-    var(--NONE) 1.41em,
-    var(--textarea-h-strip-selected) 1.41em,
-    var(--textarea-h-strip-selected) 1.47em /* line-height */
-  );
-}
-.projector.text.selected > svg {
-  z-index: 9;
-}
-
-.projector.text textarea {
-  outline: none;
-  resize: none;
-  width: 100%;
-  caret-color: var(--caret-color);
-  padding: 0;
-  margin: 0;
-  margin-left: -2px;
-  line-height: var(--line-height);
-  font-family: var(--code-font);
-  font-size: inherit;
-  border: none;
-  color: var(--textarea-text);
-  background: none;
-  box-shadow: inset 1px 0 0 var(--textarea-v-stripe);
-  overflow: hidden; /* hack: scrolls in chrome without this? */
-}
-
-.projector.text textarea::selection {
-  color: var(--BLACK);
-  background-color: var(--shard-selected);
-}
-
-/* Probe */
-
-.projector.probe  {
-  font-family: var(--code-font);
-  font-size: var(--base-font-size);
-  color: var(--STONE);
-}
-
-.projector.probe .main {
-  display: flex;
-  flex-direction: row;
-  gap: 0.4em;
-  cursor: pointer;
-  align-items: center;
-}
-
-@keyframes rotate {
-  to {
-    transform: rotate(360deg);
-  }
-}
-
-.projector.probe .live-offside:empty + * .icon {
-  /* opacity: 30%; */
-  animation: rotate 5s linear infinite;
-}
-
-.projector.probe > svg {
-  fill: #c7e6c6;
-  filter: drop-shadow(0.7px 0.7px 0px green);
-}
-
-.projector.probe.indicated > svg {
-  fill: var(--G0);
-  /* fill: #a4d7a2; */
-}
-
-.projector.probe .num-closures {
-  position: absolute;
-  right: -0.5em;
-  top: -0.3em;
-  transform-origin: top right;
-  scale: 0.6;
-  color: oklch(1 0 0);
-  font-family: var(--ui-font);
-  display: flex;
-  justify-content: center;
-  background-color: var(--G0);
-  border-radius: 2em;
-  font-size: 0.7em;
-  padding: 0.3em;
-  min-width: 1em;
-  z-index: var(--code-emblems-z);
-}
-.projector.probe.selected .num-closures {
-  background-color: var(--Y1);
-}
-
-.projector.probe .live-offside {
-  display: flex;
-  flex-direction: row;
-  position: absolute;
-  left: 10em;
-  gap: 0.15em;
-}
-
-.projector.probe .live-offside:empty  {
-  display: none;
-}
-
-.projector.probe .val-resize {
-  cursor: pointer;
-}
-
-.projector.probe .val-resize .code-text {
-  background-color: #c7e6c6;
-  border-radius: 0.4em 0.1em 0.1em 0.1em;
-  filter: drop-shadow(0.7px 0.7px 0px green);
-}
-.projector.probe .closure:first-child .val-resize:hover .code-text {
-  cursor: col-resize;
-}
-.projector.probe .val-resize.cursor .code-text {
-  outline: 1.6px solid var(--G0);
-  outline-style: dotted;
-  filter: none;
-  opacity: 100%;
-}
-
-.projector.probe .val-resize .code-text {
-  opacity: 40%;
-}
-.projector.probe .val-resize:not(.cursor) .code-text .token {
-  filter: saturate(0);
-}
-/* .projector.probe .val-resize.cursor .code-text {
-  opacity: 80%;
-} */
-.projector.probe.indicated .val-resize .code-text {
-  opacity: 60%;
-}
-.projector.probe.indicated .main {
-  color: white;
-}
-.projector.probe.indicated .val-resize.cursor .code-text {
-  opacity: 100%;
-  /* outline: 1px solid var(--GB1); */
-  outline: 2.8px solid oklch(0.7 0.15 150.31);
-}
-.projector.probe.indicated .closure:hover .live-env {
-  display: block;
-}
-.projector.probe.indicated .closure.cursor .live-env:empty {
-  display: none;
-}
-/* .projector.probe .closure:hover .live-env {
-  display: block;
-} */
-.projector.probe .closure:hover .live-env:empty {
-  display: none;
-}
-
-.projector.probe .live-env {
-  background-color: var(--T3);
-  border-radius: 0 0.2em 0.2em 0.2em;
-  padding: 0.2em;
-  display: none;
-  position: absolute;
-  top: 1.5em;
-  z-index: var(--code-hovers-z);
-}
-
-.projector.probe .live-env .live-env-entry {
-  display: flex;
-  flex-direction: row;
-  gap: 0.3em;
-  align-items: baseline;
-  color: var(--GB0);
-} 
diff --git a/src/util/JsUtil.re b/src/util/JsUtil.re
index 4002e92596..e84c34b69e 100644
--- a/src/util/JsUtil.re
+++ b/src/util/JsUtil.re
@@ -205,13 +205,7 @@ let releasePointerCapture = (e: Js.t(Dom_html.element), pointerId: int) =>
     [|Js.Unsafe.inject(pointerId)|],
   );
 
-// let hasPointerCapture = (e: Js.t(Dom_html.element), pointerId: int): bool =>
-//   Js.Unsafe.meth_call(
-//     e,
-//     "hasPointerCapture",
-//     [|Js.Unsafe.inject(pointerId)|],
-//   );
-
+// TODO: Figure out why this doesn't work
 // let on_pointermove =
 //     (handler: Js.t(Dom_html.pointerEvent) => Effect.t(unit)): Attr.t =>
 //   Virtual_dom.Vdom.Attr.property("onpointermove", Js.Unsafe.inject(handler));
diff --git a/src/util/ListUtil.re b/src/util/ListUtil.re
index e6a5c6a6c5..300d280b3b 100644
--- a/src/util/ListUtil.re
+++ b/src/util/ListUtil.re
@@ -593,7 +593,7 @@ let minimum = (f: 'a => int, xs: list('a)): option('a) =>
   };
 
 /* Given two lists, return their maximum common suffix */
-let max_common_suffix = (a: list('a), b: list('a)) => {
+let max_common_suffix = (a: list('a), b: list('a)): list('a) => {
   let rec loop = (a, b, acc) =>
     switch (a, b) {
     | ([], _)