Inference: Presumably, he keeps land with a tree more than he keeps a path with a pit or cistern;

Summation of question: Regarding a buyer, it is opposite according to R. Akiva! [The buyer] has a path when he bought a pit or cistern, and one who bought a tree does not have land!

Answer (Ri): It is obvious to [the Makshan] that Rabanan apply the reason "he made a remnant";

Even without Rav Huna, we know that the reason "he made a remnant" helps according to Rabanan to keep land with a tree, just like a path with a pit.

Explanation: E.g. the trees are barren, so due to those trees we do not consider them [too] dense. Since they do not bear Peros, they are destined to be uprooted more than the other trees;

This is like we say in Bava Basra (83b) if there was a cedar tree between them what is the law? He said, he acquired. I.e. they are not considered [too] dense.

Implied question: Why couldn't he establish it like R. Akiva?

Answer: Since he holds that one sells generously, we should say that he is Makdish more generously than one who is Makdish;

However, now that he holds like Rabanan, who do not hold at all that one sells generously, it is fine that he holds that also one is not Makdish generously.

Explanation #1 (Rashbam): He challenges Rav Huna, who said that according to Rabanan, he keeps land with the tree;

Here we find that R. Shimon holds like Rabanan, and even so, he does not keep land when he keeps a carob tree, for he says "they nurture from Hekdesh."

Implied question: Why does it say (72b) "but it is difficult..."?

Answer: We ask, rather than asking from R. Shimon against Rav Huna, you should ask a contradiction in R. Shimon himself! How can you say that he holds like Rabanan?

Question #1: The Gemara should have said "[it is difficult also] according to you"!

Question #2: Initially, we asked that if [he holds like] Rabanan, obviously he keeps land with the trees to seed [it], and now we ask that also according to Rabanan he does not keep land, for R. Shimon holds like Rabanan!

Explanation #2 (Ri): We do not challenge Rav Huna at all. Just the contrary, we come to defend his initial words, what we said "even according to R. Akiva...";

We ask "can you establish R. Shimon like R. Akiva? You are forced to say that R. Shimon is like Rabanan, and according to Rabanan, obviously he keeps land, like we said above";

If so, R. Shimon contradicts himself. How did R. Shimon say that they nurture from Hekdesh? You are forced to say that R. Shimon addressed Rabanan according to their words;

If so, also Rav Huna's teaching is fine. He said even according to R. Akiva...

Rav Huna's teaching is even like R. Akiva. Also according to [Rav Huna], R. Shimon addressed Rabanan according to their words.

Implied question: Why does it say "but it is difficult..."?

Answer #1: We ask, how did you answer the contradiction in R. Shimon?

Explanation #3 (Rashba): The question is only against Rav Huna. If not for Rav Huna, there is no contradiction in R. Shimon;

It is only because Rav Huna said that if they fall, he plants them again, R. Shimon contradicts himself;

Since R. Shimon holds like Rabanan, if so, they do not nurture from Hekdesh's field.

However, if you will say that if they fall, he may not plant them again, even though R. Shimon holds like Rabanan, still they nurture from Hekdesh;

Since if they fall, Hekdesh takes effect automatically, Stam he intends for carob and sycamore trees to be Hekdesh with the land.

Support (and Answer #2 to Question (g)): This is why it says "however, it is difficult...", i.e. for Rav Huna, who says that if they fall, he may plant them again, the question returns. Why did R. Shimon say "since they nurture from a Hekdesh field"?

Assertion (Rashbam): The text does not say so.

Rebuttal #1: There was no need to say so. What is the source to say that he is Makdish stingily, if not from this that was taught "[if he was Makdish] one after the other, he was not Makdish land"? I.e. he kept land.

Rebuttal #2: I explained above (37b) that it is proven that he is Makdish stingily, since the Reisha did not teach "he redeems, and redeems again." (If he was Makdish generously, we would say that it is in a way that increases the redemption!) We can explain also that he keeps land;

I.e. it is obvious to you that according to Rabanan, he keeps land. How did R. Shimon say above that he does not keep land?

Assertion: The text does not say "when the father died and afterwards [the son] was Makdish, no verse is needed." We properly need a verse for this!

Rather, R. Yehudah and R. Shimon know from reasoning that the same applies when [the son] was Makdish and afterwards the father died, for they follow the time of redemption.

Explanation: Rather, it is in the text in Gitin (48a. There we say that they argue about Kinyan Peros, like the next Dibur explains. Without a verse, R. Yehudah and R. Shimon know that it is like a Sedei Achuzah.) Scribes erred and wrote it also here.

Observation: We could have rejected and said that they argue about Kinyan Peros. R. Yehudah and R. Shimon hold that Kinyan Peros is not like Kinyan ha'Guf;

We do not need a verse for when his father died and then the son was Makdish it, for this is a full Sedei Achuzah, for in his father's lifetime he owned only Peros [until Yovel. He acquired the land itself only through his father's death];

We need a verse only for when he was Makdish it and then his father died. (It was not truly a Sedei Achuzah. It was merely proper to become a Sedei Achuzah.) Their reason is not because it depends on the time of redemption;

R. Meir holds that [Kinyan Peros] is like Kinyan ha'Guf. We need a verse for when his father died and then the son was Makdish it, for he did not inherit anything. It was his [also] before his father died [due to Kinyan Peros].

Support: In Gitin, this is how we wanted to establish the argument.

Implied question: Why can't we say that [R. Shimon] says his own reasoning?

Answer: He holds that even if he was Makdish a tree, he was not Makdish land, like the Beraisa teaches. All the more so he was not Makdish with the field land needed for the tree, like I explained above.