ut is backed up to the point
of recovery and the parse is resumed normally (executing all actions).
If the parse cannot be continued far enough, then another token is
discarded and the parser again tries to parse ahead.  If the end of
input is reached without making a successful recovery (or there was no
suitable error recovery state found on the parse stack to begin with)
then error recovery fails.

<a name="continuation_symbols"></a>
<h4>6.2 Viable continuation Symbols</h4>
<p>In case of parsing errors, C