Protocol spec: more vertical spacing fixes.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

protocol/protocol.tex

@@ -1991,7 +1991,7 @@ electronic commerce and payment, financial privacy, proof of work, zero knowledg
 \Large \coauthora\affiliation — \coauthorb\affiliation — \coauthorc\affiliation}
 \date{\today}
 \maketitle
-\vspace{-6ex}
+\vspace{-6ex}\sprout{\vspace{-3ex}}
 
 \notsprout{
 \begin{center}
@@ -2012,7 +2012,7 @@ succinct non-interactive arguments of knowledge (\zkSNARKs). It attempted
 to address the problem of mining centralization by use of the \Equihash
 memory-hard proof-of-work algorithm.
 
-\vspace{1.5ex}
+\notsprout{\vspace{1.5ex}}
 \sprout{\noindent This specification defines the \Zcash consensus protocol
 as it was at launch, and explains its differences from \Zerocash and \Bitcoin.
 It is a historical document and no longer specifies the current \Zcash
@@ -2026,7 +2026,7 @@ at launch, and after each of the upgrades codenamed \Overwinter, \Sapling, and
 \Blossom. It is a work in progress. Protocol differences from \Zerocash and
 \Bitcoin are also explained.}
 
-\vspace{2.5ex}
+\sprout{\vspace{1ex}}\notsprout{\vspace{2.5ex}}
 \noindent \textbf{Keywords:}~ \StrSubstitute[0]{\keywords}{,}{, }.
 
 \ifxetex
@@ -2043,6 +2043,7 @@ This document was built with Lua\TeX, which is \href{https://github.com/zcash/zi
 
 \end{abstract}
 
+\sprout{\vspace{-2ex}}
 \phantompart{Contents}{contents}
 
 \renewcommand{\contentsname}{}
@@ -6325,6 +6326,7 @@ No other security properties commonly associated with \hashFunctions are needed.
 These \hashFunctions are \emph{not} \collisionResistant for variable-length inputs.
 }
 
+\introlist
 \theoremlabel{thmpedersenencodeinjective}
 \begin{theorem}[The encoding function $\PedersenEncode{\paramdot}$ is injective]\end{theorem}
 
@@ -6368,6 +6370,7 @@ is \collisionResistant under the same assumptions and security bounds.
 Because $\ExtractJ$ is injective, it follows that $\PedersenHash$ is equally
 \collisionResistant\!.
 
+\introlist
 \theoremlabel{thmnohashtouncommittedsapling}
 \begin{theorem}[$\UncommittedSapling$ is not in the range of $\PedersenHash$]\end{theorem}
 
@@ -7623,6 +7626,7 @@ $\SubgroupJ$ is of odd-prime order.}
 
 % <https://github.com/zcash/zcash/issues/2234#issuecomment-333360977>
 \vspace{-2ex}
+\introlist
 \theoremlabel{lemmasubgroupnegation}
 \begin{lemma}[Let $P = (u, \varv) \in \SubgroupJ$. Then $(u, -\varv) \notin \SubgroupJ$]\end{lemma}
 
@@ -7642,6 +7646,7 @@ since $\SubgroupJ$ is of odd order \cite{KvE2013}).
 \end{proof}
 
 \vspace{-3ex}
+\introlist
 \theoremlabel{thmselectuinjective}
 \begin{theorem}[$\Selectu$ is injective on $\SubgroupJ$]\end{theorem}
 
@@ -11321,6 +11326,7 @@ We will need the theorem below about $y$-coordinates of points on
 \fact{$\ParamM{A}^2 - 4$ is a nonsquare in $\GF{\ParamS{r}}$.}
 
 \vspace{-1ex}
+\introlist
 \theoremlabel{thmmontynotzero}
 \begin{theorem}[$(0, 0)$ is the only point with $y = 0$ on certain \MontgomeryCurves]
 
@@ -11718,6 +11724,7 @@ a point on the relevant curve. If that is the case, the theorems below
 enumerate all exceptional inputs that may violate the side-conditions.
 
 \vspace{-1ex}
+\introlist
 \theoremlabel{thmconversiontomontnoexcept}
 \begin{theorem}[Exceptional points (ctEdwards $\rightarrow$ Montgomery)]
 
@@ -11733,6 +11740,7 @@ obtain $\varv = \pm 1$, and by substituting $\varv = 1$ and using $a \neq d$ we
 \end{proof}
 
 \vspace{-4ex}
+\introlist
 \theoremlabel{thmconversiontoedwardsnoexcept}
 \begin{theorem}[Exceptional points (Montgomery $\rightarrow$ ctEdwards)]