How long is animal A inside region R?

Strategy:

• find the scenes where A is inside R

• extract the interval for which this is true

• compute the length of the interval

Expressed as:

  AinsideR = [ S | S <- AnimalDB, S.interval(A,R,[(~contains,?,?)]) != Never ]

  AinsideR.interval(A,R,[(~contains,?,?)]).duration