<p>No special meaning here. The angle brackets simply denote a tuple or pair. The author chose the angle brackets to look prettier than the usual round parentheses. Thus a graph $G$ is a set of vertices $A \cup L$ and a set of edges $E$.</p>

CC BY-SA 2.5
2010-09-02T08:56:08.070Z
Ok, I thought so too but did not want to take the chance of interpreting it wrong. Thank you!
moxn
CC BY-SA 2.5
2010-09-02T09:18:20.443Z
It's standard to use angle brackets where the things to the rights are dependent on things to the left, as in this case, and, say, in the definition of an algebraic structure.  For something like Cartesian coordinates, normal parentheses are more normal.
Charles Stewart
CC BY-SA 2.5
2010-09-02T12:30:49.430Z
Ah, okay. I didn't know that. Thx
moxn
CC BY-SA 2.5
2010-09-02T17:05:17.703Z
It's a bit sloppy, because apparently they mean for A and L to be the two sides of a bipartition but their notation doesn't actually express that. One sometimes sees something more like (A,L,E) for denoting bipartite graphs, for this reason.
David Eppstein
CC BY-SA 2.5
2010-09-02T08:53:20.013Z
2010-09-02T08:53:20.013Z
Dave Clarke
<p>Angle bracket is often used to represent the pairing function.
Find more information here<a href="https://mathworld.wolfram.com/PairingFunction.html" rel="nofollow noreferrer">https://mathworld.wolfram.com/PairingFunction.html</a>.</p>

CC BY-SA 4.0
2020-07-17T11:44:37.823Z
2020-07-17T11:44:37.823Z
Sarkar B
<p>I am currently reading a paper and I don't know how to interpret this notation you can see on the screenshot.</p>

<p><a href="http://moxn.brainex.de/pub/dfg.png" rel="nofollow noreferrer" title="G=\langle A \cup L, E\rangle">http://moxn.brainex.de/pub/dfg.png</a></p>

<p><strong>Do the pointy angle brackets have a special meaning or did the author choose them just to confuse me?</strong></p>

<p>I googled it and apparently they are commonly used in group theory, which does not make much sense to me here.</p>

<p>Thanks for your input.</p>

<p>btw: The paper is called "A Formal Definition of Data Flow Graph Models" by Kavi, Buckles and Bhat, and is available <a href="http://csrl.unt.edu/~kavi/Research/IEEE-TC-1986.pdf" rel="nofollow noreferrer">here</a>.</p>

<graph-theory>
Does this notation have a special meaning?
moxn
# Does this notation have a special meaning?

(Asked by: username_0 on 2010-09-02)

I am currently reading a paper and I don't know how to interpret this notation you can see on the screenshot.

[http://username_0.brainex.de/pub/dfg.png](http://username_0.brainex.de/pub/dfg.png "G=\langle A \cup L, E\rangle")

**Do the pointy angle brackets have a special meaning or did the author choose them just to confuse me?**

I googled it and apparently they are commonly used in group theory, which does not make much sense to me here.

Thanks for your input.

btw: The paper is called "A Formal Definition of Data Flow Graph Models" by Kavi, Buckles and Bhat, and is available [here](http://csrl.unt.edu/~kavi/Research/IEEE-TC-1986.pdf).

**Tags:** graph-theory


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## 2 answers

### Answer by username_1 on 2010-09-02. Score: 5 | Accepted answer

No special meaning here. The angle brackets simply denote a tuple or pair. The author chose the angle brackets to look prettier than the usual round parentheses. Thus a graph $G$ is a set of vertices $A \cup L$ and a set of edges $E$.

> **Comments:**
> **username_0**: Ok, I thought so too but did not want to take the chance of interpreting it wrong. Thank you!  
> **username_2**: It's standard to use angle brackets where the things to the rights are dependent on things to the left, as in this case, and, say, in the definition of an algebraic structure.  For something like Cartesian coordinates, normal parentheses are more normal.  
> **username_0**: Ah, okay. I didn't know that. Thx  
> **username_3**: It's a bit sloppy, because apparently they mean for A and L to be the two sides of a bipartition but their notation doesn't actually express that. One sometimes sees something more like (A,L,E) for denoting bipartite graphs, for this reason.  

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### Answer by username_4 on 2020-07-17. Score: 0

Angle bracket is often used to represent the pairing function.
Find more information here<https://mathworld.wolfram.com/PairingFunction.html>.


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