 We modify this similarity function in order to derive a  spatio-temporal distance function for which we can show that a specific type of triangle inequality is satisfied.
<coherence>  We modify this similarity function in order to derive a  spatio-temporal distance function for which we can show that a specific type of triangle inequality is satisfied.
 We modify this similarity function to derive a spatio-temporal distance function for which we can show that a specific type of triangle inequality is satisfied.