+\langle s_i, s_o, \mathcal{GRE}(s)\rangle\\
+{[push_{sos}]} \qquad
+\langle push, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\
+{[roll_{sos}]} \qquad
+\langle roll, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\
+{[inchar_{sos}]} \qquad
+\langle inchar, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\
+{[innum_{sos}]} \qquad
+\langle innum, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\
+{[outchar_{sos}]} \qquad
+\langle outchar, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\
+{[outnum_{sos}]} \qquad
+\langle outnum, s_i, s_o, s\rangle \Rightarrow
+\langle s_i, s_o, s\rangle\\