Pfaffians

例句：

1. 1. The Pfaffian group is a mathematical theory that has been studied for decades.
   Pfaffian群是一种被研究了几十年的数学理论。
2. 2. The Pfaffian group is a mathematical theory that has been studied for decades.
   Pfaffian群是一种被研究了几十年的数学理论。
3. 3. The Pfaffian group is a mathematical theory that has been studied for decades.
   Pfaffian群是一种被研究了几十年的数学理论。