求英文翻译下面帮忙翻译下专业知识不给力啊翻好再加分谢谢Letα1beastringin(VT∪VN)*andα→βbearuleinP.Ifαisinα1,wecanobtainanewstringfromα1bysubstitutingαwithβ.Thenewstringisal

Question

求英文翻译
下面帮忙翻译下 专业知识 不给力啊 翻好再加分 谢谢
Let α1 be a string in (VT ∪ VN)* and α → β be a rule
in P. If α is in α1, we can obtain a new string from α1 by
substituting α with β. The new string is also a string in (VT ∪
VN)*. (The symbol * indicates a free manoid X* over the
set X). Now, let α2 denotes the new string. α2 is said to be
derivable from A1 in G.
The derivation can be expressed as α1 → α2. Let
α1, α2, α3,.., αm be strings in (VT ∪ VN)* (M ≥ 2).
If the are α1 → α2, αm−1 → αm, then αm is said to
be derivable from α1 in G. The sequence of derivations
α1 → α2, ..., αm−1 → αm is referred to as a derivation chain
from α1 to αm. A grammar G defines a language L(G). A
string s is a valid sentence in L(G), if and only if s =⇒ S.
VN翻译器出来时越南 各位能给力点不···

Answer 1

将α1看作是(VT ∪ VN)* 集合内的一串字符,α → β是P规则集下的一个规则.如果α属于α1,我们可以把β代入α,从α1推导出一个新字串.新的字串仍然属于(VT ∪ VN)* 字串集.（* 符号代表一个集合X里的独异点X*).现在,...