This is a 80 year old who presented to the ED with abdominal pain.
 The patient has a history of abdominal surgery 
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (DT a) (ADJP (CD 80) (NN year) (JJ old))) (SBAR (WHNP (WP who)) (S (VP (VBD presented) (PP (TO to) (NP (DT the) (NN ED))) (PP (IN with) (NP (JJ abdominal) (NN pain)))))))) (. .)))
(ROOT (S (NP (DT The) (NN patient)) (VP (VBZ has) (NP (NP (DT a) (NN history)) (PP (IN of) (NP (JJ abdominal) (NN surgery)))))))
( This ( ( is ( ( a ( 80 ( year old ) ) ) ( who ( ( presented ( to ( the ED ) ) ) ( with ( abdominal pain ) ) ) ) ) ) . ) )
( ( The patient ) ( has ( ( a history ) ( of ( abdominal surgery ) ) ) ) )