I am trying to reproduce the equation of the image below. I am using an `array`

environment to create the first big curly brace. I have tried to nest a second `array`

to produce a second curly brace, but I get an error.

This is the code that gave me an error:

```
DTW(A,B)=\left\{ \begin{array}{l}
0 \quad \text{se $n$=0 ed $m$=0}\\
\infty \quad \text{se $n$=0 o $m$=0}\\
d(H(A),H(B))+\min\left\{
\begin{array}{1}
a\\
b\\
c\\
\end{array}
\right.
\end{array} \right.
```

How can I write this equation?

## Best Answer

You have a typo in your inner array

change

to