Simplified return data setting for return from deployment (#723)

hub/generalities/context/numbers.tex

@@ -29,27 +29,28 @@
 	\item \If \big($\peekStack_{i} = 1$ \et $\haltFlag_{i} = 1$\big) \Then $\cn\new_{i} = \caller_{i}$
 \end{enumerate}
 \saNote{} \label{hub: generalities: context: consequences of CMC and XAHOY}
-Constraints~(\ref{hub: generalities: context: whenever the context may change the final row is a context row}) and
-(\ref{hub: generalities: context: exceptions lead to providing empty return data}) may seem inconspicuous and cryptic but they are \textbf{very important}.
+Constraint~(\ref{hub: generalities: context: whenever the context may change the final row is a context row}) and
+constraint~(\ref{hub: generalities: context: exceptions lead to providing empty return data})
+may seem inconspicuous and cryptic but they are \textbf{very important}.
 In light of the definition of the \CONTEXTMAYCHANGE{} flag given in section~(\ref{hub: generalities: context: cmc flag}),
 constraint~(\ref{hub: generalities: context: whenever the context may change the final row is a context row})
 enforces that every time the \zkEvm{} encounters
 a \inst{CALL}-type instruction ($\stackDecCallFlag \equiv 1$),
 a \inst{CREATE}-type instruction ($\stackDecCreateFlag \equiv 1$),
-a halting instruction ($\stackDecHaltFlag \equiv 1$),
-or raises an exception ($\xAhoy \equiv 1$),
+a halting instruction ($\stackDecHaltFlag \equiv 1$) or
+raises an exception ($\xAhoy \equiv 1$),
 instruction processing \textbf{must end on a context row}.
-This manifests all over instruction handling,
-see section~(\ref{hub: instruction handling}),
+This manifests all over instruction handling~(\ref{hub: instruction handling})
 in extraneous constraints of the form
 \[
-	\left\{ \begin{array}{l}
-	        \nonStackRows _{i} = \texttt{<numerical value>} + \cmc_{i}                                                                \\
-		\texttt{<peeking flag sum>} = \texttt{<functional peeking flag sum>} + \peekContext_{i + \yellowm{\omega}} \cdot \cmc_{i} \\
+	\left\{ \begin{array}{lclcr}
+		\nonStackRows _{i}          & = & \overbrace{\texttt{<numerical value>}}^{\yellowm{\omega}} & + & \cmc_{i}                                           \\
+		\texttt{<peeking flag sum>} & = & \texttt{<functional flags>}                              & + & \peekContext_{i + \yellowm{\omega}} \cdot \cmc_{i} \\
 	\end{array} \right.
 \]
-Furthermore constraint~(\ref{hub: generalities: context: exceptions lead to providing empty return data}) ensures that
-in case of an exception, this context row is one \textbf{squashing the parent context's return data.}
+Furthermore,
+constraint~(\ref{hub: generalities: context: exceptions lead to providing empty return data})
+ensures that in case of an exception, this context row is one \textbf{squashing the parent context's return data.}
 
 \saNote{} \label{hub: generalities: context: automatic gas checks}
 Further note that $\cmc \equiv 1$ along with section~(\ref{hub: lookups: into gas}), triggers the \gasMod{} module.
@@ -60,4 +61,4 @@
 
 \saNote{} Constraint~(\ref{hub: generalities: context: how to trigger finalization phase}) settles the question of when execution stops and the finalization phase starts.
 
-\saNote{} We refer to section~\ref{hub: context-rows: specialized constraints} for the definition of $\executionProvidesEmptyReturnData {i}{\relof}$.
+\saNote{} We refer to section~(\ref{hub: context-rows: specialized constraints}) for the definition of $\executionProvidesEmptyReturnData {i}{\relof}$.

hub/generalities/refunds/constraints.tex

@@ -18,16 +18,16 @@
 \end{enumerate}
 The above is the transition constraint for gas refunds.
 
-Recall that \textbf{along stack-rows} one has
+Recall that \textbf{along stack-rows} (i.e. whenever $\peekStack \equiv 1$) one has
 \[
-		\stackDecStoFlag \cdot \decFlag{1} \equiv 1  \quad \text{precisely for \inst{SSTORE}, see section~(\ref{hub: instruction handling: sto});}
+	\stackDecStoFlag \cdot \decFlag{2} \equiv 1  \iff \stackInst \equiv \inst{SSTORE} \text{, see section~(\ref{hub: instruction handling: sto});}
 \]
 \begin{enumerate}[resume]
 	\item \If $\cnWillRev_{i} = 1$
 		\Then $\refund\new_{i} = \refund_{i}$
-	\item \If $\peekStack_{i} = 1$ \et $\stackDecStoFlag  _{i} \cdot \decFlag{1}_{i} = 0$
+	\item \If $\peekStack_{i} = 1$ \et $\stackDecStoFlag  _{i} \cdot \decFlag{2}_{i} = 0$
 		\Then $\refund\new_{i} = \refund_{i}$
-	\item \If $\cnWillRev_{i} = 0$ \et $\peekStack_{i} = 1$ \If $\stackDecStoFlag_{i} \cdot \decFlag{1}_{i}  = 1$ \Then \dots{} see section~(\ref{hub: instruction handling: sto})
+	\item \If $\cnWillRev_{i} = 0$ \et $\peekStack_{i} = 1$ \If $\stackDecStoFlag_{i} \cdot \decFlag{2}_{i}  = 1$ \Then \dots{} see section~(\ref{hub: instruction handling: sto})
 \end{enumerate}
 The above thus enforces that
 (\emph{a}) execution context that will revert don't contribute to the refunds