Fischer and Rabin’s *Super-Exponential Complexity of Presburger Arithmetic* (1974) has the following theorem.

(Theorem 12) Let $U$ be any class of additive structures, so if $A = (A, +) in U$,

then $+$ is a binary associative operation on $A$. Let Th($U$) be the set of sentences

of $L$ valid in every structure of $U$. Assume $U$ has the property that, for every

$k in mathbb N$, there is a structure $A_k = (A_k, +) in U$ and an element $u in A_k$ such that

the elements $u, u + u, u + u + u, … , k . u$ are distinct. Then the statement of

Theorem 1 holds for Th($U$) with the lower bound $2^ {dn}$ for some $d > 0$.

The conclusion that Th($U$) is at least exponential time. They don’t provide a proof for this (they say they will in a subsequent paper, which I believe has never appeared), but they say that their proof for the theory of the real numbers can be adapted by using $ku$ as a representation for $k$.

Is there a more detailed exposition of a proof of this theorem? The following points are not clear to me:

- The exact hypothesis of this theorem is unclear to me. On one hand, they say “additive”, use the symbol $+$, and list abelian groups or expansions thereof as examples after stating this theorem. On the other hand, they do not explicitly say “commutative” or “abelian”; it may be sufficient to assume associativity if we are applying the operation to $u, u+u, dots$ to represent natural numbers because commutativity is not an issue as long as these elements are concerned.
- Presumably, one needs to say in the language ${+}$ that $u, dots ku$ are distinct in order to use them as representation for natural numbers up to $k$. One also needs very large $k$ to simulate Turing machines. How can one ensure that $u$ has the desired property with a relatively short logical formula?

]]>

I want to open a java web application (Mirth Connect) on my Ubuntu machine. So following the tips on this page I installed icedtea:

```
sudo apt-get install icedtea-netx
```

and then executed the jnlp file I downloaded:

```
javaws webstart.jnlp
```

I then get this screen:

And whichever button I press (Yes, No, close) it constantly reloads this screen and refuses to proceed to the rest of the application.

On my Mac this application works perfectly well.

Does anybody know why this happens on Ubuntu, and how I can get it to work?

]]>

**System Settings** will lose icons if the **Appearance > Theme** is set to *High Contrast*. The Launcher can also lose some icons. Changing back to the default *Ambiance* will restore icons after a while but not necessarily immediately.

How can *High Contrast* be used without the loss of icons?

This pertains to Ubuntu 16.04.

]]>

Our company creates an ejb in two artifacts. The impl artifact contains the implementations and the client artifact contains all the interfaces. This means that the impl artifact has a compile dependency on the client artifact.

Now at runtime, the client artifact needs the impl artifact – otherwise the container cannot inject the required objects. This means that an ear needs to contain the impl artifacts for all client artifacts.

Does this mean that the client artifact should have a `runtime`

dependency on the impl artifact? Or should these “circular” dependencies be avoided, even if one direction is `compile`

and the other is `runtime`

?

]]>

My openSuse Tumbleweed installation has somehow stopped booting at all. The startup process goes through normally, but then it says `A start job is running for Hold until boot process finishes up (7 min / no limit)`

and that’s it. No matter how much I wait there seems to be no way for it to finish whatever it’s doing. Using `Ctrl`+`Alt`+`F1` or any other combination only brings me to the same problem. The only thing that seems to work is the old REISUB key sequence to reboot the whole thing.

As asked here’s my hardware configuration:

- ASUS PRIME X370-PRO motherboard with lastest BIOS update
- Ryzen 5 1500X processor running at stock clock speed
- Nvidia GTX 1060 3GB
- Kingston HyperX 2133Mhz 8gb RAM memory

The Nvidia card is running the propietary software, which is working well pre-update (even though it was hard to get it running)

I’m on kernel version 4.15.0-1-default, which gets updated when I run `sudo zypper dup`

.

EDIT: I’ve rolled back my installation to a point before updating the system (using snapper), and it works fine. Then I tried to update again, and it brought me to the same problem. What can I do besides leaving my system outdated?

]]>

I am creating temporary table during stored procedure execution with the following structure:

```
[ID] BIGINT
[Point] GEOGRAPHY
```

the `ID`

is not unique – there are about `200`

records for each `ID`

.

I need to find a list with distinct `IDs`

for which there is at least one `Point`

to `Point`

distance larger then constant value (for example `200`

meters).

So, I am using something like this:

```
SELECT DISTINCT DS1.[ID]
FROM DataSource DS1
INNER JOIN DataSource DS2
ON DS1.[ID] = DS2.[ID]
WHERE DS1.Point.STDistance(DS2.Point) > 200
```

For 23 000 points, the query is executed for `4-5`

seconds. As I am expecting to have more values, I need to find better solution.

I guess that if there is faster way, I can always create a materialized table and implement additional logic that will calculated this on `ID`

base.

I have created a spatial index, but the query optimizer is not using it. If I use a `hint`

like this `WITH (INDEX(SPATIAL_idx_test))`

I am getting the following error:

Msg 8635, Level 16, State 4, Line 78

The query processor could not produce a query plan for a query with a spatial index hint. Reason: Spatial indexes do not support the comparator supplied in the predicate. Try removing the index hints or removing`SET FORCEPLAN`

.

`

]]>

My openSuse Tumbleweed installation has somehow stopped booting at all. The startup process goes through normally, but then it says `A start job is running for Hold until boot process finishes up (7 min / no limit)`

and that’s it. No matter how much I wait there seems to be no way for it to finish whatever it’s doing. Using `Ctrl`+`Alt`+`F1` or any other combination only brings me to the same problem. The only thing that seems to work is the old REISUB key sequence to reboot the whole thing.

As asked here’s my hardware configuration:

- ASUS PRIME X370-PRO motherboard with lastest BIOS update
- Ryzen 5 1500X processor running at stock clock speed
- Nvidia GTX 1060 3GB
- Kingston HyperX 2133Mhz 8gb RAM memory

The Nvidia card is running the propietary software, which is working well pre-update (even though it was hard to get it running)

I’m on kernel version 4.15.0-1-default, which gets updated when I run `sudo zypper dup`

.

EDIT: I’ve rolled back my installation to a point before updating the system (using snapper), and it works fine. Then I tried to update again, and it brought me to the same problem. What can I do besides leaving my system outdated?

]]>

I’m using libreoffice as a pdf converter inside a docker container by utilising the headless functionality. How can I disable macros? I’m using debian strech-9.3 and libreoffice 5.4.5

]]>

Fischer and Rabin’s *Super-Exponential Complexity of Presburger Arithmetic* (1974) has the following theorem.

(Theorem 12) Let $U$ be any class of additive structures, so if $A = (A, +) in U$,

then $+$ is a binary associative operation on $A$. Let Th($U$) be the set of sentences

of $L$ valid in every structure of $U$. Assume $U$ has the property that, for every

$k in mathbb N$, there is a structure $A_k = (A_k, +) in U$ and an element $u in A_k$ such that

the elements $u, u + u, u + u + u, … , k . u$ are distinct. Then the statement of

Theorem 1 holds for Th($U$) with the lower bound $2^ {dn}$ for some $d > 0$.

The conclusion that Th($U$) is at least exponential time. They don’t provide a proof for this (they say they will in a subsequent paper, which I believe has never appeared), but they say that their proof for the theory of the real numbers can be adapted by using $ku$ as a representation for $k$.

Is there a more detailed exposition of a proof of this theorem? The following points are not clear to me:

- The exact hypothesis of this theorem is unclear to me. On one hand, they say “additive”, use the symbol $+$, and list abelian groups or expansions thereof as examples after stating this theorem. On the other hand, they do not explicitly say “commutative” or “abelian”; it may be sufficient to assume associativity if we are applying the operation to $u, u+u, dots$ to represent natural numbers because commutativity is not an issue as long as these elements are concerned.
- Presumably, one needs to say in the language ${+}$ that $u, dots ku$ are distinct in order to use them as representation for natural numbers up to $k$. One also needs very large $k$ to simulate Turing machines. How can one ensure that $u$ has the desired property with a relatively short logical formula?

]]>

My openSuse Tumbleweed installation has somehow stopped booting at all. The startup process goes through normally, but then it says `A start job is running for Hold until boot process finishes up (7 min / no limit)`

and that’s it. No matter how much I wait there seems to be no way for it to finish whatever it’s doing. Using `Ctrl`+`Alt`+`F1` or any other combination only brings me to the same problem. The only thing that seems to work is the old REISUB key sequence to reboot the whole thing.

As asked here’s my hardware configuration:

- ASUS PRIME X370-PRO motherboard with lastest BIOS update
- Ryzen 5 1500X processor running at stock clock speed
- Nvidia GTX 1060 3GB
- Kingston HyperX 2133Mhz 8gb RAM memory

The Nvidia card is running the propietary software, which is working well pre-update (even though it was hard to get it running)

I’m on kernel version 4.15.0-1-default, which gets updated when I run `sudo zypper dup`

.

EDIT: I’ve rolled back my installation to a point before updating the system (using snapper), and it works fine. Then I tried to update again, and it brought me to the same problem. What can I do besides leaving my system outdated?

]]>