class_docstr: This class holds the broken-down components of a hole semantics, i.e. it
  extracts the holes, labels, logic formula fragments and constraints out of
  a big conjunction of such as produced by the hole semantics grammar.  It
  then provides some operations on the semantics dealing with holes, labels
  and finding legal ways to plug holes with labels.
class_docstr_tok: ["This","class","holds","the","broken-down","components","of","a","hole","semantics",",","i.e",".","it","extracts","the","holes",",","labels",",","logic","formula","fragments","and","constraints","out","of","a","big","conjunction","of","such","as","produced","by","the","hole","semantics","grammar",".","It","then","provides","some","operations","on","the","semantics","dealing","with","holes",",","labels","and","finding","legal","ways","to","plug","holes","with","labels","."]
docstr: Return true if x is a node (label or hole) in this semantic
  representation.
docstr_tok: ["Return","true","if","x","is","a","node","(","label","or","hole",")","in","this","semantic","representation","."]
code: def is_node(self, x):
      """
      Return true if x is a node (label or hole) in this semantic
      representation.
      """
      return x in (self.labels | self.holes)
  
imports: from functools import reduce
  from nltk.parse import load_parser
  from nltk.sem.logic import AllExpression, AndExpression, ApplicationExpression, ExistsExpression, IffExpression, ImpExpression, LambdaExpression, NegatedExpression, OrExpression
  from nltk.sem.skolemize import skolemize
label_desc: Use image node_id 2 for calling the HoleSemantics obj's underlying member method code with example usage: obj.is_node(x) and returns: unknown