diff --git a/design/duvenhage-inner-recursion-activity-diagram.puml b/design/duvenhage-inner-recursion-activity-diagram.puml
index 107631c2697fd2d3a83e4c0d38ce31ea426adbb8..04efd176e4ee4604a12b3027d0f960110a27e178 100644
--- a/design/duvenhage-inner-recursion-activity-diagram.puml
+++ b/design/duvenhage-inner-recursion-activity-diagram.puml
@@ -47,22 +47,22 @@
     end note
     stop
   endif
-  :previous ← start;
-  : crossings ← line-of-sight segment crossings of next level sub-tiles;
+  :previous ⇦ start;
+  : crossings ⇦ line-of-sight segment crossings of next level sub-tiles;
   note right
     crossings can be computed either
     using flat body hypothesis
     or taking curvature into account
   end note
   repeat
-    :intersection ← recurse(previous, crossing);
+    :intersection ⇦ recurse(previous, crossing);
     if (found intersection?) then (yes)
       : return intersection;
       stop
     endif
-    :previous ← crossing;
+    :previous ⇦ crossing;
   repeat while (more crossings?)
-  :intersection ← recurse(previous, end);
+  :intersection ⇦ recurse(previous, end);
   : return intersection;
   stop
 
diff --git a/design/duvenhage-top-loop-activity-diagram.puml b/design/duvenhage-top-loop-activity-diagram.puml
index 44b856d4ed2076642ff43d6bba071c5a0a14a856..773abc72a9e4a4165ffd4069773223b348764b5f 100644
--- a/design/duvenhage-top-loop-activity-diagram.puml
+++ b/design/duvenhage-top-loop-activity-diagram.puml
@@ -29,30 +29,30 @@
   skinparam ActivityFontSize                    11
 
   start
-  : gp₀ ← point at altitude 0;
+  : gp₀ ⇦ point at altitude 0;
   : select tile containing gpâ‚€;
-  : current point ← null;
-  : hmax ← tile maximum elevation;
+  : current point ⇦ null;
+  : hmax ⇦ tile maximum elevation;
   while (current point is null)
-    : entry ← point at altitude hmax;
+    : entry ⇦ point at altitude hmax;
     if (locate entry point) then (in selected tile)
     else (outside of selected tile)
       : select tile containing entry point;
-      : hmax ← max(hmax, tile maximum elevation);
-      : current point ← null;
+      : hmax ⇦ max(hmax, tile maximum elevation);
+      : current point ⇦ null;
     endif
   endwhile
   repeat
-    : exit ← line-of-sight exit point from tile;
-    : intersection ← Duvenhage(current, exit);
+    : exit ⇦ line-of-sight exit point from tile;
+    : intersection ⇦ Duvenhage(current, exit);
     if (found intersection?) then (yes)
       : return intersection;
       stop
     endif
     if (tile exited at side?) then (no)
-      : searching ← false;
+      : searching ⇦ false;
     else (yes)
-      : forward point ← point slightly after exit point;
+      : forward point ⇦ point slightly after exit point;
       : select tile containing forward point;
       if (DEM traversed between\ncurrent and forward points) then (yes)
         : return current point;
@@ -61,7 +61,7 @@
         end note
         stop
       endif
-      : current point ← forward point;
+      : current point ⇦ forward point;
     endif
   repeat while (searching ?)
   :search failed;