On page 113 Munkres (Topology: Second Edition) defines a J-tuple as follows:
I was somewhat perplexed when I tried to completely understand the function .
I tried to write down some specific and concrete examples but still could not see exactly how the function would work.
For example if and X was just the collection of all the letters of the alphabet i.e.
then ...
... obviously a map like 1 --> a, 2 --> d, 3 --> h does not work as the intention, I would imagine is to have a mapping which specifies a number of triples ... but how would this work?
[Just to clarify what I mean: I imagined, as an example a mapping by x such that
1 mapped to a
2 mapped to d
3 mapped to h
However, although this is a mapping from J to X under the function x it does not really define a set of triples.]
Can someone either correct my example or give a specific concrete example that works.
Would appreciate some help.
Peter