# Math Help - Quick Q about intervals

1. ## Quick Q about intervals

If a closed interval (in R) has positive length does that mean that it can be written out like $(a_1 , a_2 , a_3 , ... , a_n)$

2. It always dangerous to answer a question about notation. It is not always standard.
Usually a closed interval means: $a < b\,\& \,[a,b] = \left\{ {x:a \leqslant x \leqslant b} \right\}$.