Special notations for Repetitive Constructs Notation for repetition as regular expressions use, the asterisk A→Ba,and A→0*B eBNF opts to use curly brackets i. to express repetition A→B{c},and A→{aB The problem with any repetition notation is that it obscures how the parse tree is to be constructed, but, as we have seen, we often do not care.Special Notations for Repetitive Constructs • Notation for repetition as regular expressions use, the asterisk * . A →  * , and A → *  • EBNF opts to use curly brackets {. . .} to express repetition A →  { } , and A → {}  • The problem with any repetition notation is that it obscures how the parse tree is to be constructed, but, as we have seen, we often do not care