Grammar Kit RecoverWhile

Hello,

I'm sorry to ask for help again , but I'm having a hard time figuring out how to make a recoverWhile works.

I’ve read the HOWTO several times and thought I had understood but it doesn’t works.

pin(".*Definition")=1

cupSpec ::= packageDeclaration? importDeclaration* classNameDeclaration? codeParts* symbols+
precedences* startWith? production+

private symbols         ::= terminalDefinition | nonTerminalDefinition
                        | typedNonTerminalDefinition | typedTerminalDefinition
{recoverWhile= symbols_recover}
private symbols_recover ::= !('terminal' | 'non' | 'nonterminal')
terminalDefinition      ::= 'terminal' termNameList
typedTerminalDefinition ::= 'terminal' typeId termNameList
nonTerminalDefinition   ::= ( 'non' 'terminal' |'nonterminal' ) termNameList
typedNonTerminalDefinition ::= ( 'non' 'terminal' |'nonterminal' ) typeId termNameList

typeId                  ::= qualifiedName
termNameList            ::= identifier (',' identifier)* ';'
qualifiedName           ::= identifier ('.' identifier)*

And when I test with this :

terminal ADD, MUL, PO, PF;
terminal NUM;

nksvojnsv
sijffo

non terminal l;
non terminal x, f, a;

Nothing goes wrong, the PSI tree looks good (the bad input is not present in it) but my Annotator highlighting goes down and I don't have any error highlighting.

Can someone explain me where is my stupid mistake ?

Thanks you !