# functional analysis – singular distributions

I am doing a report on wavelets (the book is A. Cohen, Numerical Analysis of Wavelets Methods), but I am not really into Hilbert spaces, so I have some problems with notation. The book use quite often (e.g. proof of theorem 2.8.1) a notation: $$delta_{2pi n}^{(q)}$$, saying that it is a singular distibution supported at the origin only. But how does exactly works? What does it means the $$(q)$$ and $$2pi n$$ (hoping it is a quite standard notation)?