1 | initial version |

There is a problem since the `a`

you are using seems to come from a previous computation.

At least on the last version of Sage, if you type

```
sage: K = GF(2^7,'a');
```

The python variable `a`

does not point to the generator of `K`

whose name is `'a'`

```
sage: a
NameError: name 'a' is not defined
```

For this, you have to do:

```
sage: K.inject_variables()
Defining a
```

Then, everything seems to work:

```
sage: PK.<x>=K[];
sage: f = (a^6 + a^3 + a)*x^2 + (a^6 + a^4 + a^3)*x + (a^5 + a^4 + a^3 + a^2 + 1);
sage: print f.roots();
[(a^3 + a, 1), (a^5 + a^3 + a^2 + a, 1)]
```

2 | No.2 Revision |

There is a problem since the variable `a`

you are using in your third line seems to come from a previous computation.

At least on the last version of Sage, if you type

```
sage: K = GF(2^7,'a');
```

The python variable `a`

does not point to the generator of `K`

whose name is `'a'`

```
sage: a
NameError: name 'a' is not defined
```

For this, you have to do:

```
sage: K.inject_variables()
Defining a
```

Then, everything seems to work:

```
sage: PK.<x>=K[];
sage: f = (a^6 + a^3 + a)*x^2 + (a^6 + a^4 + a^3)*x + (a^5 + a^4 + a^3 + a^2 + 1);
sage: print f.roots();
[(a^3 + a, 1), (a^5 + a^3 + a^2 + a, 1)]
```

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