Subroutine 3Sequence Processing Subroutine ($\sigma ,S,E$)

Input: Any sequence $\sigma$, given ordered list S and event set E Output: A split-list $SL$ obtained from splitting $\sigma$ by S and E sequentially   ${\sigma }_0\leftarrow \sigma$   $SL$ = $\leftarrow \varnothing$   for $s_i$ in S$(i\in [1,\left|S\right|\left]\right)$ do    ${\sigma }_i\leftarrow$ replace $s_i$ by ’-’+$s_i$+’-’ in ${\sigma }_{i-1}$   end for   ${\sigma }_{\left|S\right|}$.replace(’–’,’-’)   for each symbol $sp$ in ${\sigma }_{\left|S\right|}[1:-1]$.split(’-’) do    if $sp$ in S then     $SL$.append($sp$)    else     $SL$.append($sp$ split by basic events $e_i$)    end if   end for   return $SL$