Is Using \leq for Subgroup Notation Incorrect?

  • Thread starter Thread starter kntsy
  • Start date Start date
  • Tags Tags
    Notation Subgroup
AI Thread Summary
The use of \leq to denote that H is a subgroup of S is a common practice in mathematical notation, despite its origins in numerical comparisons. While some argue that this notation is misleading because it traditionally represents less-than-or-equal relationships, it is widely accepted as long as the context is clearly defined. Alternative notations, such as H ⊆ G, are also used, but they may require contextual interpretation to indicate subgroup status. The discussion highlights that mathematical notation can be overloaded, allowing for flexibility in symbol usage. Overall, the notation \leq for subgroups is prevalent and not considered incorrect in many mathematical contexts.
kntsy
Messages
80
Reaction score
0
my lecturer use \leq for subgroup.
For example
H \leq S means H is a subgroup of S.
But is it a wrong use of notation as the less-than-equal sign is about number?
 
Mathematics news on Phys.org
No, there are, after all, only a finite number of symbols and an infinite number of possible concepts in mathematics! As long as you are careful to say how you are using a symbol, you can "overload" it.
 
Moreover, this is a frequent notation. See for instance this online course: http://user.math.uzh.ch/halbeisen/4students/gt.html"

Go to "Subgroups"
 
Last edited by a moderator:
arkajad said:
Moreover, this is a frequent notation. See for instance this online course: http://user.math.uzh.ch/halbeisen/4students/gt.html"

Go to "Subgroups"

In fact, I've never seen this notation not used.
 
Last edited by a moderator:
Newtime said:
In fact, I've never seen this notation not used.

In some books any special notation for H being a subgroup of G is carefully avoided. Words are always being used. In some other books it is written H\subset G and you have to deduce from the context that H is a subgroup of G.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Thread 'Imaginary Pythagoras'
I posted this in the Lame Math thread, but it's got me thinking. Is there any validity to this? Or is it really just a mathematical trick? Naively, I see that i2 + plus 12 does equal zero2. But does this have a meaning? I know one can treat the imaginary number line as just another axis like the reals, but does that mean this does represent a triangle in the complex plane with a hypotenuse of length zero? Ibix offered a rendering of the diagram using what I assume is matrix* notation...
Back
Top