After a given substring has been isolated $($current$),$ updates to the subsequences list $($subs$)$ depend on several variables:

Is current in the second string?

Is current already in subs?

Is the length of current smaller, equal or larger than the strings in subs already?

While there are several boolean variables, there are only three outcomes. What are they? $($The first one has been provided.$)$ What conditions apply for each?

$\backslash$table$[[$#$,$Outcome,Conditions$],[1,$No changes to subs,$],[2,,],[3,,]]$