Temporal Relations in multimedia   

Not all the theoretically possible relations are 

  required 

< VS <=

  what is the difference between " e1 is 1 millisecond 

  before e2 " and "e1 is simultaneous to e2 "

   <=, >= are not needed

    If we focus on consistent scenarios, ø  is also 

     unnecessary.

    What we need are:  < = > ?