An install reply's :fns and flan reload's summary name each fn once, as it is written.

bin/main.ml

@@ -878,7 +878,7 @@ let () =
       (* [as] where the other path has [llc], which is the number the whole
          backend exists to move. Named for what ran. *)
       Printf.eprintf "%s  %s  %s %.1fms  ld %.1fms\n" out
-        (String.concat " " c.Flan.Session.fns)
+        (String.concat " " (Flan.Session.shown_fns c))
         (if x86 then "as " else "llc") timing.Flan.Build.llc_ms
         timing.Flan.Build.link_ms)
   (* [run] builds and execs. A .wasm is not executable, and picking a runtime

emacs/test-flan.el

@@ -1920,6 +1920,18 @@ already rely on it — so nothing here is a stand-in for the real thing."
                           (user-error (setq raised (error-message-string err))))
                         (and raised (string-match-p "not a function" raised))))
 
+    ;; A fn with several arities is compiled under a name per arity, and the
+    ;; install is said with the name written, once.
+    (let* ((file (concat socket3 "-arities.flan"))
+           (r (flan--request
+               (list :op "eval" :file file
+                     :code "(defn grp ([a i64] i64 a) ([a i64 b i64] i64 (+ a b)))")))
+           (said (test-flan--said (flan--report r "form"))))
+      (test-flan--check "a fn with two arities is installed under the name written, once"
+                        (and said
+                             (string-match-p "\\`flan: grp installed in" said)
+                             (not (string-match-p "~\\|(also" said)))))
+
     ;; A generic has no code under its own name, only a copy per type it is
     ;; called at, so its name is answered with those: refused while there are
     ;; none, and one listing per copy, each headed by its types, once there

lib/dev.ml

@@ -1180,7 +1180,7 @@ let eval ?forms ?base ?(extra = []) ?(step = false) t ~code ~origin ~pause =
               c.Session.fns;
             ok
               ([ ":names " ^ Wire.strings c.Session.names;
-                 ":fns " ^ Wire.strings c.Session.fns;
+                 ":fns " ^ Wire.strings (Session.shown_fns c);
                  Printf.sprintf ":ms %.1f"
                    (timing.Build.llc_ms +. timing.Build.link_ms) ]
                @ stale_field c.Session.stale

lib/session.ml

@@ -690,6 +690,18 @@ type change = {
   stale : stale list;
 }
 
+(* The bodies a change installed, as whoever reads the reply wrote them: a
+   fn with several arities is compiled under a name per arity, and is one
+   name to the person who sent it. [fns] itself stays by symbol — the
+   daemon's module ownership is keyed on it. *)
+let shown_fns (c : change) =
+  List.fold_left
+    (fun acc f ->
+       let n = Check.written_name f in
+       if List.mem n acc then acc else n :: acc)
+    [] c.fns
+  |> List.rev
+
 (* [pause] is [C-u C-c C-c]: the position, in the source just sent, of the form
    the program should stop at — TODO.org, "A breakpoint is marked from the
    editor, without editing the buffer". It arrives as a separate field

test/test_session.ml

@@ -99,6 +99,9 @@ let () =
     | Some c ->
       if List.sort compare c.Session.fns <> [ "outer~0"; "outer~2" ] then
         fail "two arities installed %s" (String.concat " " c.Session.fns);
+      (* The reply's :fns, which the editor says: the name written, once. *)
+      if Session.shown_fns c <> [ "outer" ] then
+        fail "two arities were shown as %s" (String.concat " " (Session.shown_fns c));
       if c.Session.stale <> [] then fail "two arities left a caller behind"
     | None -> ());
    (match eval "the form again" "(defn outer ([] i64 (bump)) ([a i64 b i64] i64 (* a b)))" with