( Perhaps ( , ( ( in ( the future ) ) ( , ( we ( ( will ( ( ( describe ( ( a ( machine 's ) ) behavior ) ) , ) ( not ( ( ( ( in ( terms ( of ( ( the ( simple sequences ) ) ( of ( events ( described ( in ( ( today 's ) rules ) ) ) ) ) ) ) ) ) , ) but ) ( in ( terms ( of ( ( the ( ( more complex ) patterns ) ) ( of ( events ( contained ( in ( the tests ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) ) ) )
(ROOT (S (ADVP (RB Perhaps)) (, ,) (PP (IN in) (NP (DT the) (NN future))) (, ,) (NP (PRP we)) (VP (MD will) (VP (VB describe) (NP (NP (DT a) (NN machine) (POS 's)) (NN behavior)) (, ,) (PP (RB not) (PP (IN in) (NP (NP (NNS terms)) (PP (IN of) (NP (NP (DT the) (JJ simple) (NNS sequences)) (PP (IN of) (NP (NP (NNS events)) (VP (VBN described) (PP (IN in) (NP (NP (NN today) (POS 's)) (NNS rules)))))))))) (, ,) (CC but) (PP (IN in) (NP (NP (NNS terms)) (PP (IN of) (NP (NP (DT the) (ADJP (RBR more) (JJ complex)) (NNS patterns)) (PP (IN of) (NP (NP (NNS events)) (VP (VBN contained) (PP (IN in) (NP (DT the) (NNS tests))))))))))))) (. .)))
Perhaps, in the future, we will describe a machine's behavior, not in terms of the simple sequences of events described in today's rules, but in terms of the more complex patterns of events contained in the tests.
(ROOT (S (S (NP (DT A) (JJ complex) (NN machine)) (VP (VBZ is) (VP (VBN described) (PP (IN by))))) (: :) (S (NP (PRP it)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (QP (JJR more) (IN than) (CD one)) (JJ simple) (NN machine)))))) (. .)))
A complex machine is described by: it is made of more than one simple machine.