mathematical symbol for vector appending

Given a vector v=<1,2,3>, now I want to have a new vector v', which is the vector v, appends with a number 4, how should I represent v' mathematically?

What I wish to have is something like v'=v^4=<1,2,3,4>, where ^ is an appending symbol for vector (therefore my main question is, does it exist such "vector appending" symbol in maths?)

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What do you mean by appending? What is "type alphabet"? –  EuYu Nov 15 '12 at 2:18
As a rule of thumb, you generally want the task of answering your question to be harder than the task of understanding what is being asked... –  anon Nov 15 '12 at 2:19
Thanks for the comment:) question edited. –  william007 Nov 15 '12 at 2:59
This question has also been asked at tex.SE: tex.stackexchange.com/questions/8397 –  Douglas S. Stones Nov 15 '12 at 3:02