They also justified that the popular "early update" (Collins and Roark, 2004) is valid for the systems that do not exhibit spurious ambiguity 4 .
this can be efficiently implemented (without explicitly enumerating ) by checking if each LEFt(i)/RIGHt(i) in y are compatible with ( ): p i already collected all its dependents according to t; p i is attached to the correct neighbor suggested by t. For English, we use PtB as our data set.