In this verse, we have the momentary loss in 𝓟 of the of in “the city of Zeezrom”. 𝓞 is extant here, and the of is definitely there. In fact, every city in this conjoining of city names has the of in the original text. But in the last example, “the city of Antiparah”, the 1849 LDS edition omitted the of. The subsequent 1852 LDS edition followed the 1849 reading, “the city Antiparah”, in the first printing, but the of was restored in the second printing, probably by reference to the 1840 edition.
As noted under 1 Nephi 11:13, for each case of “city (of) X”, we follow the earliest textual sources with respect to the of. Thus the of will be maintained for “the city of Zeezrom” and “the city of Antiparah” here in Alma 56:14. This is the only occurrence of “city (of) Zeezrom” in the Book of Mormon text. The phrase “city (of) Antiparah” occurs eight times in the text. Besides the case with the original of here in Alma 56:14, there are four instances with the of; these are all found at the beginning of Alma 57:
In none of these cases has the original of ever been removed. On the other hand, there are three instances of “the city Antiparah” later in chapter 56, and for each of these cases there has been a strong tendency in the printed editions to add the of:
For the first example, the of was added in the 1837 edition and has been retained in every subsequent edition. For the two other examples, the 1841 British edition added the of, but the 1920 LDS edition removed it from the LDS text.
Summary: Follow the earliest textual sources with respect to the of for every case of “city (of) X” in the text; for the phrase “the city (of) Antiparah”, the original text had five instances with the of and three without; the only instance in the text of “the city (of) Zeezrom”, in Alma 56:14, has the of.