Tremaux formulated rules by which an explorer or searcher could visit every point of a connected maze and return to his entry point. Without much difficulty his rules can be generalized to the case of search by a number of people where it is required that every point be visited by one searcher or another. It will be gratifying if it turns out that the method is practical for use in the recovery of disaster victims or lost property in buildings or districts.
  It is assumed that the maze is finite and that any access point not used by a searcher is regarded as blanked off.
  Searchers may start from any point in the maze or on its boundary as long as the number of searchers there does not exceed the number of ways from it. Then they can and should start off in different directions.    
  The rules for each searcher are:
  1. When possible he takes a route not previously searched by anyone. If two or more searchers arrive at a junction at the same time any priority applies.
  2. When Rule1 cannot be applied, that is if he comes to a dead end, meets another searcher in a passage or comes to a junction where there is no previously unused route he backtracks, that is follows in reverse the route by which he arrived at that point, ignoring any passage he has already done both ways, till he comes to a point where Rule1 applies. Or if there is no such point he will return to his start-point and then his search is over.
  Following these rules each searcher will come back to his starting point having been along a number of passages once in one direction and once in the other direction. By these two rules and connectedness every passage gets searched.

  Copyright Nov2005 conesetter.