Re:Visual Group Theory: What is a group? (2016) [video]
by filmor on Saturday February 10, 2018 @06:54AM
(#16346936)
>> one-to-one and onto funktion
>
> I don't think that's the established terminology.
It is. Injective and surjective are more "international", but those English names are fine as well. What's missing is that the function sshould map a set onto itself.
Re:Visual Group Theory: What is a group? (2016) [video]
by smadge on Tuesday February 13, 2018 @01:47AM
(#16365222)
> Injective and surjective are more "international", but those English names are fine as well
Thanks! one-to-one and onto is the terminology my American courses are using.
> What's missing is that the function sshould map a set onto itself.
Just for the record I initially stated "a permutation is just a one-to-one and onto function from a set to itself" as you say it must.
I don't think that's the established terminology.
> How do you propose to interpret all of these groups geometrically,
How do you not? This pure maths wank really grinds my gears. Of course you can substitute other perceptive phenomena next to the visual. But even your abstract thoughts have to be accomodated in the geometry of the brain, if you think about it.