/*  Stage 1. Linear Expansion Algorithm (LE)       */
/*  For a tail                     */
If  Priority == “ 𝑇 ” then /*  Last robot in the line       */
 if  Object detected ∧   Object   ≤  assigned sonar range limit then
  Stop driving;
 else
  repeat
   Search for RSSI of AP root 1 “ 𝑅 1 ”;
  until “ 𝑅 1 ” RSSI found;
  if “ 𝑅 1 ” RSSI   ≤  assigned RSSI threshold limit then
    Stop driving;
  else
   Drive straight;
Algorithm 3: The LE algorithm for a tail.