Eruvin 77B

שמקצת עלין מגולין אינו חושש לא משום כלאים, ולא משום מעשר, ולא משום שביעית, וניטלין בשבת!

some of the leaves of the turnip or radish are showing, he need not be concerned due to diverse kinds, i.e., that he violated the prohibition of planting food crops in a vineyard, as he did not intend to commit an act of planting; nor due to tithes, i.e., there is no concern lest the turnip or radish grew further, in which case he would be obligated to tithe it; nor due to the prohibition against working the land during the Sabbatical Year, and similarly, he need not be concerned that they grew further and that the additional growth is prohibited as produce that grew during the Sabbatical Year. And therefore, the turnip or radish may be taken from the ground on Shabbat. Even if most of the turnip or radish is underground, it is permitted to pull it from the ground on Shabbat. If so, in the case described in the Mishnah here, even if the basin buried in the ground has a rim, it should nevertheless be permitted to move it.

לא צריכא, דבעי מרא וחצינא.

The Talmud answers: No, R' Yeḥiel’s ruling is necessary in a case where the basin was so firmly attached to the ground that one would need a hoe [mara] or a spade to remove it, as this action would certainly involve digging, which is prohibited on Shabbat. Therefore, since the basin cannot be removed on Shabbat, it is considered fixed in its place and effectively diminishes the height of the wall.

סולם המצרי אינו ממעט והצורי ממעט. היכי דמי סולם המצרי? אמרי דבי רבי ינאי: כל שאין לו ארבעה חווקים.

It was taught in a baraita: An Egyptian ladder, which is small, does not diminish the height of a wall, whereas a larger, Tyrian ladder effectively diminishes its height. The Talmud asks: What are the circumstances of an Egyptian ladder; i.e., what characterizes it? The scholars of the school of R' Yannai said: Any ladder that does not have 4 rungs.