وَمِنْ شَرَائِطِهَا: الْجَمَاعَةُ، وَأَقَلُّهُمْ عِنْدَ أَبِي حَنِيفَةَ: ثَلَاثَةٌ سِوَى الْإِمَامِ، وَقَالَا: اثْنَانِ سِوَى الْإِمَامِ.
Translation: Congregation is a condition. Abu Hanifah requires three people besides the imam; Abu Yusuf and Muhammad require two besides the imam.
Abu Hanifah: four people in total, including the imam.
Abu Yusuf and Muhammad: three in total, including the imam.
The issue is the smallest body qualifying as the Friday congregation; Shafi‘i law sets a different minimum.