Hello, @Cyrille!

Concerning (1), remember: the best way to typeset a string as LaTeX output in Sage is using the `LatexExpr`

function/class, instead of using a pair of `$`

. So, in order to outputting `A =`

as LaTeX, just do `LatexExpr('A = ')`

:

```
show(LatexExpr('A ='), A)
```

Notice the matrix `A`

itself doesn't need to be wrapped with a `LatexExpr`

, since it is not a string.

Concerning (2), matrices have rings associated to them, and Sage "coerces" (I believe that's the technical word) the ring to the most general one that fits the contents of the matrix. In your case, the presence of `oo`

is making Sage assume your matrix should be associated with the `The Infinity Ring`

, as you can see yourself if you write `bmax.base_ring()`

. This ring assumes something is infinity ($+\infty$, $-\infty$ or an unsigned $\infty$), zero or something finite. Unfortunately, this makes the ring almost blind to everything finite. For example, if you write

```
InfinityRing(7) == InfinityRing(800)
```

you will get `True`

, which shows you that this ring considers $7$ and $800$ the same.

Anyway, the solution is to specify another ring. In this case, you have to use `SR`

(the symbolic ring):

```
bmax = matrix(SR, m, 1, (oo,10,70))
```

or

```
bmax = matrix(m, 1, (oo,10,70), ring=SR)
```

This will give you:

WARNING: If you are trying to use the `bmin`

and `bmax`

arguments of `add_constraint`

, I think you should stick to lists of values, instead of matrices. For example, you can use `bmax = [oo, 10, 70]`

while working the Linear Problem, and once you solve it, you can use `show(matrix(SR, m, 1, bmax))`

. Otherwise, the matrix ring seems to interfere with the constraint definition.

Where, in which environment is missing the display (since i am starting sage either in a linux console, or in an eclipse / pycharm IDE)? And on which platform?