1 | initial version |

There is no such command in Sage. But the rank is just obtain from conditions on the minors of the matrix.

```
sage: t = polygen(ZZ, 't')
sage: M = matrix([[t,0],[0,1]])
sage: M.minors(2)
[t]
sage: M.minors(1)
[t, 0, 0, 1]
```

In other words:

your matrix has rank 2 if $t \not= 0$

otherwise if $t \not= 0$ and $1 \not= 0$ your matrix has rank 1

otherwise your matrix has rank 0 (never happen)

2 | No.2 Revision |

There is no such command in Sage. But the rank is just obtain from conditions on the minors of the matrix.

```
sage: t = polygen(ZZ, 't')
sage: M = matrix([[t,0],[0,1]])
sage: M.minors(2)
[t]
sage: M.minors(1)
[t, 0, 0, 1]
```

In other words:

if $t \not= 0$ your matrix has rank

~~2 if $t \not= 0$~~2otherwise if $t \not= 0$

~~and~~or $0 \not= 0$ or $1 \not= 0$ your matrix has rank 1otherwise your matrix has rank 0 (never happen)

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