Grammar grammaire;
Lexer
id = ('a'..'z')+;
altid = '{' id ':}';
str = '\'' (Any* - '\'') '\'';
blank = ' ' | #9 | #10 | #13;

Parser
Ignored blank;
prods = {many:} prods prod  | {one:} prod ;
prod = id '=' alts ';' ;
alts = {many:} alts '|' alt | {one:} alt ;
alt = altid atoms | atoms ;
atoms = {many:} atoms atom | {none:} ;
atom = {id:} id | {str:} str ;