Vertical space between different types of footnotes in manyfoot

Question

I am using the manyfoot package to create three different types of footnotes. How can I change the vertical space between the different types of footnotes in a document?

Here is my MWE:

\documentclass[12pt, twoside]{book}

\usepackage{manyfoot}
\usepackage[nodisplayskipstretch]{setspace}

\SetFootnoteHook{\scriptsize \setstretch{1.2}}
\DeclareNewFootnote{A}[alph]

\SetFootnoteHook{\tiny}
\DeclareNewFootnote{B}[roman]

\begin{document}

Here\footnote{First type of footnotes.} is some text with three\footnoteA{Second type of footnotes.} different types of footnotes\footnote{Another footnote of first type.}\footnoteA{Another footnote of second type.}\footnoteB{Third type of footnotes.}.

\end{document}

Answer 1

Each new footnote is assigned a new "insert" with the name \footins followed by the label; in this case, \footinsA and \footinsB. An insert is a length, count and box with the same register value.

Normally the length \footins is used to store the distance above the \footnoterule. For the new footnotes it is used to store the space between the groups.

\documentclass[12pt, twoside]{book}

\usepackage{manyfoot}
\usepackage[nodisplayskipstretch]{setspace}

\SetFootnoteHook{\scriptsize \setstretch{1.2}}
\DeclareNewFootnote{A}[alph]

\SetFootnoteHook{\tiny}
\DeclareNewFootnote{B}[roman]

\setlength{\skip\footinsA}{0pt}
\setlength{\skip\footinsB}{0pt}

\begin{document}
Here\footnote{First type of footnotes.} is some text with three\footnoteA{Second type of footnotes.} different types of footnotes\footnote{Another footnote of first type.}\footnoteA{Another footnote of second type.}\footnoteB{Third type of footnotes.}.

\end{document}