Shabbat daf 6-7: Karmelit

At the bottom of Shabbat 6b, going on to 7a:

The Master said: 'But the sea, a plain, a colonnade, and a karmelith rank neither as public nor as private ground.' But is a plain neither private nor public ground? Surely we learnt: A plain: in summer it is private ground in respect to the Sabbath and public ground in respect to uncleanness;¹²  in winter it is private ground in both respects!¹³  — Said 'Ulla: After all it is a karmelith; yet why is it called private ground? Because it is not public ground.¹⁴  R. Ashi said: E.g., when it has barriers,¹  and [this is] in accordance with the following dictum of 'Ulla in R. Johanan's name: An enclosure more than two se'ahs [in area]²  which is not enclosed in attachment to a dwelling place,³  even if it is a kor or two kor [in area],⁴  if one throws [an article] therein [from public ground] he is liable. What is the reason? It is a partitioned area, but it lacks inhabitants.⁵  Now, as for R. Ashi, it is well that he does not explain it as 'Ulla;⁶  but why does 'Ulla not explain it in accordance with his own dictum? — He answers you: if it has barriers, is it called a plain: [surely] it is an enclosure! And R. Ashi?⁷ — 'Private ground' is taught.⁸

This dispute between Rav Ashi and Ulla can be classified as a dispute between Bavli and Yerushalmi. Rav Ashi is the redactor of Bavli, while Ulla is an Amora from Eretz Yisrael. Indeed, if we turn to Yerushalmi, we will find that it is in line with Ulla. In Yerushalmi Berachot 5b (with the commentary of the always excellent Yedid Nefesh embedded):

ים ובקעה ואיסטווה מקום שיושבים הסוחרים לפני החנות ואסקופה מפתן שאצל הפתח, ורק אם רחב ד' טפחים, ואם אינו רחב הוה מקום פטור וכרמלית, אינן לא רשות הרבים ולא רשות היחיד. ואין נושאין ונותנין מטלטלים בהן מדרבנן ואם נשא ונתן בהן פטור. אמר רב יוסף אף אנן תנינן כולהן. ים, דתנינן תמן להלן פרק יא הזורק בים ארבע אמות פטור. לא סוף דבר לא רק אם זרק ד' אמות בים, אלא אפי' זורק בכל הים פטור לפי שכל הים נקרא כרמלית. בקעה, דתנינן טהרות פרק ו הבקעה, בימות החמה שאין בה זרעים רשות היחיד לשבת כי אין רבים מהלכים שם, לפי שאנשים רגילים ללכת במסילה ורשות הרבים לטומאה לעניין שספיקו טהור. ובימות הגשמים, רשות היחיד לכאן ולכאן כך היא הגירסה. כי השדה זרועה ואין נכנסים שם כלל. אם אומר את וכשאתה אומר שבימות הגשמים שדה זו רשות היחיד לכאן ולכאן, לא תהא טעונה הקפה כלי בהמה אם חנו שם איך צורך להקיף את המקום כדי שיוכלו לטלטל בתוכה דתנינן עירובין פרק א, שיירה שחנתה בבקעה הקיפוה כלי בהמה, מטלטלין בתוכה ואם רשות היחיד היא מדוע אמרו להקיף? אלא כרמלית היא, ומה שאמר רה"י הכוונה שאינה רה"ר.

That is, in analyzing the very same brayta as Bavli about the sea, plain, collonade, and karmelit, the Yerushalmi notes that it classifies it as non-reshut hayachid. And so it cites that other brayta about the plain (valley) in rainy vs. sunny season, where it is classified as reshut hayachid; and it concludes that it is not precisely reshut hayachid. Where Rav Ashi (=Bavli) would say no, it is a reshut hayachid, and we are dealing with where it has walls, the Yerushalmi says, similar to Ulla, that it could not be so, because otherwise we would not require an enclosure to be able to carry within it.

What is a karmelit, though? It appears as both the name of the class: karmelit; and as an item within the list of things which are karmelit. This is what prompts the following Bavli:

'And a karmelith.' Are then all these [sea, plain and colonnade] too not karmelith? — When R. Dimi came,⁹  he said in the name of R. Johanan: This is necessary only in respect of a corner near a street:¹⁰  though the masses sometimes press and overflow therein,¹¹  yet since it is inconvenient for [general] use, it ranks as a karmelith.

I would adopt a slightly different approach. Something is certainly off if it is the class name and an item name, and pashut peshat in the brayta is not that it is listed merely to include an otherwise unmentioned item. If this were indeed so, then Tosafot's question would indeed be a strong question. Tosafot ask why they did not include tzidei reshut harabim. And Tosafot gives a good answer, but still, it is a good question that would have deserved mention in the gemara itself, I think.

More than that, what is the etymology of karmelit? The Yerushalmi has it as:

כרמלית, תני רבי חייא כתיב (ויקרא כג, יד) ולחם קלי וכרמל, ומפרש כרמל, רך מלא נמלל ביד אינו לא לח ולא יבש אלא בינוני. והכא וגם לעניינינו הכרמלית אינה לא רה"ר ולא רה"י אלא כרמלית.

It is an in between state. Rambam suggests likewise, giving the derivation as ke-armelit, "like a widow", who is neither married nor a never-married woman, but in an in between state. (The letters in lamnar, that is lamed mem nun resh switch off with each other, such that Hebrew Almana = Aramaic Armalta.) Both of these seem like folk etymologies, which are fanciful while speaking to the known implication or common usage of the term.

But I think there was an original real meaning of the term, which derives not from a Semitic language, but from some foreign tongue, perhaps Greek or Latin. And a karmelit was a type of place, just like a collonade or a valley. But, they seized upon karmelit as an exemplar for the whole group. At that point, rabbinic sorts of people forgot, on the whole, the original meaning of karmelit as specific domain X and instead treated it as class of domain Y.

So of course karmelit is part of the class of karmelit.

What is the specific (rather than class of) domain which is a  karmelit? Rabbi Yochanan, in Yerushalmi, speaks of it as a known type of place. Thus:

איזו הא כרמלית? רבי יסא בשם רבי יוחנן כגון חנותיה דבר יוסטיני החנות של בר יוסטיני.

None of the meforshim on the daf can really define the chanut of bar Yustini, because they don't have access to contemporary knowledge.

It is a logical guess to associate the two statements of Rabbi Yochanan, namely the one cited in Yerushalmi and the one cited in Bavli. Thus, when we see in Bavli:

When R. Dimi came,⁹  he said in the name of R. Johanan: This is necessary only in respect of a corner near a street.

I would say that this is not coming to give an inclusion of a new item, which is how it is most simply understood and how it presents a difficulty to Tosafot. Rather, Rabbi Yochanan, as an early first generation Amora who had contact with Tannaim, is defining for us what was known to be the literal karmelit. Which would make this the definition of the chanut of bar Yustini.

The years of Yustini to Justinian do not work out, but there is a famous courtyard later associated with Justinian, so maybe we can put the precise reference to a later writer: Justinian's Augustaion. To cite Wikipedia:

Originating as a public market, in the 6th century it was transformed into a closed courtyard surrounded by porticoes, and provided the linking space between some of the most important edifices in the Byzantine capital. The square survived until the late Byzantine period, albeit in ruins, and traces were still visible in the early 16th century.

The square dates back to ancient Byzantium, before its conversion into an imperial capital by Constantine the Great. When Roman EmperorSeptimius Severus (r. 193–211) rebuilt the city, he erected a large square surrounded by porticoes, hence named the Tetrastoon ("four stoas"). In the center of the square stood a column with a statue of the god Helios.^[1] In the 320s, Constantine adorned his chosen new capital with many new monumental buildings. His activities included new structures around the Tetrastoon, while the Augustaion was likely carved out of its eastern part at that time, and named after a Porphyry column supporting a statue of his mother, the Augusta Helena.^[1][2] The Augustaion was rebuilt in 459 under Emperor Leo I (r. 457–474), and again in the 530s, after being destroyed in the Nika riot, by Emperor Justinian I (r. 527–565). In its original form, the square was open to the public and functioned as the city's food market (agora), but after Justinian's reconstruction, it became more of an enclosed courtyard where access was restricted. Byzantine writers from the 7th century on refer to it as explicitly as a court or forecourt (αὐλή, αὐλαία, προαύλιον) of the Hagia Sophia.^[1][2]

...

Enclosed on all sides, the Augustaion was entered in its western and southern side, respectively through the Melete and Pinsos Gates, from the Mesē, the city's main thoroughfare.^[1] Directly outside the square stood the Milion, the mile marker from which all distances in the Empire were measured. To its north, the Augustaion was bounded by the Hagia Sophia cathedral and the Patriarchal palace (Patriarcheion), to its east by one of the two Senate houses of the city, built by Constantine or Julian (r. 360–363) and rebuilt by Justinian with a porch of six great columns adorning its front.

Thus, if this is the same item the Yerushalmi refers to (!), then we are dealing with a square surrounded by porticos. Or a square, initially open to the public but later, an enclosed courtyard where access was restricted; where Justinian erected a column. We would need to work out the particulars, and scholars already have, for different time periods. But my guess is that this is somehow the karmelit to which Rabbi Yochanan refers.

Thus, this is a karmelis (3d reconstruction):