We also lifted several restrictions imposed in previous work (Bethard et al., 2007;Yoshikawa et al., 2009;Verhagen et al., 2010).
we do not require that event mentions and time expressions have to appear in the same sentence, and we do not require two event mentions have to appear very close to each other (e.g., main event mentions in adjacent sentences) in order to be considered as candidate pairs for classification.