Sub-Symbol

例句：

1. 1. The sub-symbol for thenumber 5 is a small circle witha cross inside it.
   数字5的次符号是一个小圆圈里面有一个十字。
2. 2. In mathematics, sub-symbols areused to represent values that are less thanor equal to a certain number.
   在数学中，次符号用于表示小于或等于某个特定数值的值。
3. 3. The sub-symbol for the letter'A' is a smallcircle with an arrow pointing upwards.
   字母'A'的次符号是一个小圆圈，箭头向上。