code: private PExp getImpliesExpression(AMapCompMapExp exp, ILexNameToken finmap,
  			ILexNameToken findex)
  	{
  		if (exp.getPredicate() == null) // Map comprehension has no predicate
  		{
  			return getImpliesExists(exp, finmap, findex);
  		} else
  		{
  			return AstExpressionFactory.newAImpliesBooleanBinaryExp(exp.getPredicate(), getImpliesExists(exp, finmap, findex));
  		}
  	}
docs: p(a,b) => exists idx in set dom m & m(idx) = { a |-> b }