Review Comment:
Even though the submission has improved, I find that there are still some issues with the current version. Because I would like to review the paper again before it is published, I am going to give it a "Minor Revision" score. Below, I list the main issues that I find with the submission.
1. The writeup needs to be improved. Apart from all of the minor comments that I list below, I find the following issues.
 The authors include content that (IMO) is not really necessary (e.g., Example 2 or the explanation of De Morgan's Law) and then do not define notions that are central (e.g., substitutions, unifiers, graph of rule dependencies...). As a consequence of this, it is difficult to understand some of the notions presented in the paper (e.g. Definition 2.5).
 I find that the notation used is at times a bit confusing. For instance, the notation for rules is not very clear. Instead, I would have preferred if the authors would use \wedge and \vee instead of , and []. As a result of this choice, e.g., Example 3.6 is quite unclear.
 As I pointed out in the previous version, the definitions of some notions could be unified. For instance, you can define disjunctive existential rules and then define existential rules as a restricted form of disjunctive existential rules.
 Some of the provided theorems are really difficult to read and understand. E.g., Theorem 5.
2. Presentation and motivation for the technical results.
 It is not clear from the writeup what is previous work and what is a novel contribution of the authors. For instance, are the results from Section 3 novel? What about theorems 3.2 and 3.3? This needs to be properly clarified.
 Some of the provided formal arguments are not proper proofs. E.g., the proof Theorem 3.9 needs more work.
 Doesn't Theorem 3.8 subsume 3.7? That is, if Algorithm 1 stops, then that means that all queries have rewritings. Hence, the knowledge base in Theorem 3.8 is a fus.
 Even though the authors propose many results that can be used to determine whether a knowledge base is fus, I do not believe that any of these are very useful. To validate the usefulness of these results, the authors could (1) study realworld rule sets, (2) find some rule sets not captured by any wellknown fragment that guarantees query rewritability, and (3) show that at least some of these can be characterised as fus by applying the results in this paper.
3. Issues with the evaluation
 Even though there are no other systems that can deal with negated atoms you could have still compared performance for queries without negation.
 In the paper you mention that "The OWL 2 ER fragment of both ontologies was translated into existential rules". Do you mean to say "OWL EL" instead of "OWL ER"? Furthermore, I have looked at the ontologies online and have seen that they contain inverses and functional properties. Therefore, these ontologies are not in EL. Can you explain this situation? Are the ontologies that you put online not the ontologies that you used in the evaluation?
 As far as I can tell, your implementation was capable of rewriting all the queries. Why is this the case? Are both ontologies fus? Or is it because you only consider a restricted set of queries?
Not clear what is novel versus what is not:
Theorem 3.1
Minor Comments:
 Shorten the title so there is not a line at the end with a single word.
 If you can put the "footnote asterisk" after the comma.
0. Abstract
 "for the framework of disjunctive existential rules" > "for disjunctive existential rules".
1. Introduction
 The writeup of the first paragraph is not very precise
 Line 18: do not use a line for such a short word.
 Add a ~ after \wedge in line 18 so it is not so close to the closing parenthesis.
 It appears that there is way too much empty vertical space in Example 1.1.
 "although the size of the rewriting can be exponential" > add a citation here.
 Having no restriction on the expressivity of the rules already makes the query entailment undecidable. If you mention negated atoms here, the reader will think that you need this feature for the language to be undecidable.
 It would be nice to find shortcuts so the rules given in the examples fit in a single rule. Also, you could ignore universally quantified variables, as it is usually done.
 "Conjunctive query entailment is undecidable even in the case of existential rules without disjunction" > You have mentioned this before.
 Page 2, line 24: AFAIK, CQs do not allow for the use of universal quantifiers.
 Page 2, line 30: this example does not make much sense, does it? It implies that every person is either married or is the parent of someone? Also, add ~ after the \vee operator at the end of the line.
 Page 2, line 28: modify the text so you don't have a line with just 4 letters.
 Page 2, line 40: move the citation to the end of the sentence.
 Page 2, line 51: why do you uppercase "union"?
 Page 2, column 2, line 7: what is a "rewriting operator"?"
 Page 3, column 1, line 12: remove these extremely short lines.
2. Preliminaries
 Page 3, column 2, line 11: maybe use FOL to be consistent.
 P3, C2, L25: you do not need to uppercase "Formulas". Same for the next sentence.
 P3, C2, L45: do not use the future tense.
 Definition 2.1: wouldn't it be easier to just use disjunctions and/or conjunctions instead of introducing this notation that is probably new for most readers?
 P4, C1, L45: it would be easier to say that a literal is positive or negative. In the next sentence, you can say that a formula is ground if it does not contain variables.
 Figure 1 is not a very good representation of a hypergraph because the edges are undirected. That is, by looking at the picture, I do not know whether parent(X, Z) or parent(Z, X).
 When you say that a CSF of atoms can represent a hypergraph: specify that this is a directed hypergraph.
 P4, C2, L23: connected > \emph{connected}
 P4, C2, L40: you do not need to use 3 lines here.
 P5, C1, L21: do not use the future tense. Same for the rest of the proof.
 I would not include Example 2.2.
 P5, C1, L39: do not use the future tense.
 P5, C2, L5: what is the definition of unifiable and unifier?
 P5, C2, L13: what is a most general unifier?
 In Definition 2.3: use the \emph{} environment when youintropduce a new notion.
 Definition 2.4: do not use the future tense.
 P6, C1, L51: remove that line.
 P6, C2, L1: what is a ground instance?
 Theorem 2.2: What are C1 and C2?
 P7, C1, L35: these are Boolean conjunctive queries (since you do not have universally quantified variables). Also, write "(CQ)" with parenthesis when you introduce a new shortcut.
 P7, C1, L40: "all of the variables in a query are present in positive literals"
 P7, C2, L13: comma before "i.e."
 Definition of existential rule: by your definition, the variables in \vec{Y} may appear in the body of the rule.
 "The quantification of variables follows the same rules described in the definition of an existential rule" > this does not make much sense...
 Add a citation for the graph of rule dependencies.
 It would be easier to define a knowledge base as a binary tuple consisting of a set of facts and a set of rules (disjunctive and constraints are also rules).
 Example 2.4: "Let's" > "Let us"
 P8, C1, L29: which existential rule? Also, use numbers in your equations and point to the corresponding formulas in the text.
 Usually, the notion of a UCQrewriting implies completeness. The presented notation is confusing.
 If possible, place the captions of the tables below the actual table.
 Example 3.2: the first sentence in this example is grammatically incorrect.
 Definition 3.4: the notion of a unifier should be formally introduced in this paper. Also, quantify H', q', and v. Also, include the unifier in the expression rew(r, q).
 Theorem 3.5: what is a UCQ component? The sentence after "iff" is not readable.
 In Alg. 1, you do not need to introduce so many variables.
 "In general, it is undecidable to know if there exists a finite UCQrewriting" > add citation
 P15, C1, L32: what is the purpose of this sentence?
 Next sentence: you should say "A cut for R is a partition..."
 P15, C2, L1: What is \mathcal{R} here?
 P15, C2, L26: remark that you can only use finitely many predicates, variables and constants.
 P15, C2, L29: what does this sentence mean?
 Theorem 3.9: "of of", "o"
 P17, C1, L41: the last sentence is not necessary; answers by definition only include constants.
 P17, C2, L5: don't you have to existentially quantify the variable Y? Also, write "pedro" instead of "perdo" in the previous line.
 P17, C2, L33: a variable would be assigned to a Skolem term, but not to a Skolem function.
 P17, C2, L37: what does it mean for an existential rule to produce a "disconnected existential rule"?
 Example 3.6: align the formulas that result from the constraint refutation in a different way.
 P20, C2, L1: OWL 2 ER > OWL 2 EL
 P15, C1, L12: uppercase the word "algorithms". Same with the word "algorithm" in Theorem 3.6.
 P15, C2, L40: remove lines with 1 word.
 P15, C2, L41: you have already defined disconnected rules before.
 P20, C1, L47: what are siblings concepts
