Avrohom Bornsztain

Avrohom Bornsztain (14 October 1838 – 7 February 1910), also spelled Avraham Borenstein or Bernstein, was a leading posek in late-nineteenth-century Europe and founder and first Rebbe of the Sochatchover Hasidic dynasty. He is known as the Avnei Nezer ("Stones of the Crown") after the title of his posthumously-published set of Torah responsa, which is widely acknowledged as a halakhic classic.[1] His only son, Shmuel, author of Shem Mishmuel, succeeded him as Rebbe.

Hilchos Gitten, Kav Hanaki

Hilchos Gitten, Kav Hanaki, Lubavitcher posek
wrote sefer Shaar HaKolel, birur of Baal Hatanya's sidduer of Nusach Ari, calls it that because Arizal says there are 12 gates into Jerus. one for each gate, but a 13th gate for BTs and people who don't know what shevet they are from