   
 1 SyntaxThe key notion of ITL is an interval. An interval is considered to be a (in)finite sequence of states , where a state is a mapping from the set of variables to the set of values . The length of an interval is equal to , one less than the number of states in the interval (this has always been a convention in ITL), i.e., a one state interval has length 0. The syntax of ITL is defined in Table 1 where
  

 