[nem-en] errors in reference documentation

[Kamil Dworakowski]

vc wrote:
>> Apart from the extra s on the right side there is also the mistake of
>> using {} where [{}] is needed. Am I right?
>>     
>
> In many EBNF notations {} traits as "0 or more".
>
>   
I remember {} to mean once or more from cs courses. To my surprise it 
appears that iso standard of EBNF says it is 0 or more. It is good that 
conventions in the reference manual are stated explicitly.

Kamil Dworakowski