Minor tweak

syndicate/HOWITWORKS.md

@@ -295,8 +295,7 @@ cases where handlers are dynamically installed.
                       classof (project v h) = class }
               edges[selector][class] := ((innercache, {}), {})
           let node' = edges[selector][class]
-          let h' = h ++ [0]
-          walk-edge h' node' 0 0 [s_0, ..., s_i]
+          walk-edge (h ++ [0]) node' 0 0 [s_0, ..., s_i]
 
 **Definition.** The `addHandler` procedure installs into an index an
   event handler callback `f` expecting values matching and captured by