Update the spec with decommit offchain changes (#7)

Signed-off-by: Sasha Bogicevic <sasha.bogicevic@iohk.io>

hydra-protocol/Hydra/Protocol/Figures/fig_offchain_prot.tex

@@ -82,10 +82,19 @@
 
 						%%% REQ SN
 						\On{$(\hpRS,v,s,\mT_{\mathsf{req}}, \tx_{\omega})$ from $\party_j$}{
-							\Req{$v = \hatv ~ \land ~ s = \hats + 1 ~ \land ~ \hpLdr(s) = j$} \;
-							\Wait{$\hats = \bar{\mc S}.s$}{
-								\Req{$\bar{\mc S}.U \applytx \tx_{\omega} \not= \bot$} \;
-								$U_{\mathsf{active}} \gets \bar{\mc S}.U \applytx \tx_{\omega} \setminus \mathsf{outputs(\tx_{\omega})}$ \;
+                                \Req{$s = \hats + 1 ~ \land ~ \hpLdr(s) = j$} \;
+							    \Wait{$ v = \hatv ~ \land ~ \hats = \bar{\mc S}.s$}{
+							    % TODO: waiting for version observed is way longer than for no snapshot in flight!
+								\If{$v = \bar{\mc S}.v ~ \land ~ \bar{\mc S}.\tx_{\omega} \neq \bot$ }{
+									\Req{$\bar{\mc S}.\tx_{\omega} = \tx_{\omega}$} \;
+									$U_{\mathsf{active}} \gets \bar{\mc S}.U$ \;
+									$U_{\omega} \gets \bar{\mc S}.U_{\omega}$
+								}
+								\Else{
+									\Req{$\bar{\mc S}.U \applytx \tx_{\omega} \not= \bot$} \;
+									$U_{\mathsf{active}} \gets \bar{\mc S}.U \applytx \tx_{\omega} \setminus \mathsf{outputs(\tx_{\omega})}$ \;
+									$U_{\omega} \gets \mathsf{outputs}(\tx_{\omega})$
+								}
 								\Req{$U_{\mathsf{active}} \applytx \mT_{\mathsf{req}} \not= \bot$} \;
 								$U \gets U_{\mathsf{active}} \applytx \mT_{\mathsf{req}}$ \;
 								$\hats \gets s$ \;