帮忙分析这句有过去分词和and的英语长句？

Question

The problem of finding a shortest edit script reduces to finding a path from (0,0) to (N,M) with the fewest
number of horizontal and vertical edges. Let a D-path be a path starting at (0,0) that has exactly D non-diagonal
edges. A 0-path must consist solely of diagonal edges. By a simple induction, it follows that a D-path must consist
of a (D − 1)-path followed by a non-diagonal edge and then a possibly empty sequence of diagonal edges called a
snake.

问题是从By a simple induction ... 开始, 弄不清之后的几个定语是修饰哪个名词.
1. 在followed by a non-diagnal edge修饰的是D-path还是(D-1)-path?
2. and then是和it follows并列还是和a non-diagnal并列?
3. called a snake是修饰diagonal edges? a D-path? a (D-1)-path? a non-diagonal edge? a possibly empty sequence?

Answer 1

同学，首先，对于这段话描述的事情/概念，你有没一个基本的了解？不要让英语牵着你走。找到最短的脚本编辑的问题去减少用最少的水平与垂直的边界从(0,0)到(N,M)找到一个路径。使D一个成为从(0,0)开始，直接包含（D非对角线的边界）的路径。同学这个是数学问题吧，具体的概念如果你清楚就用学过的相关知识来解读，如果没有基本的概念，只能被牵着走了。0路径必须由单独的对角边界组成。用一个简单说明，它包含以下情况（元素），一个D路径必须由一个连着一个非对角边界的及一个可能无顺序的对角边界（也叫做一条蛇）的D-1路径组成。同学把句子的主干（主谓宾找出来，其他非谓语找出，从句找出，再其他修饰成分对应连上就可以了）。

Answer 2

这句话的主干结构是
By a simple induction, it follows that a D-path must consists of A and (then) B.，而其中A是a (D-1)-path，B是a possibly empty sequence of diagonal edges.其余部分：分词短语followed by a non-diagnal edge作A的后置定语，called a snake作B的后置定语。
于是
1. followed by a non-diagnal edge修饰的是(D-1)-path.
2. and then既不和it follows并列，也不和a non-diagnal edge并列。理由：若和前者并列，由于句子结构复杂，在and后面会紧跟一个that以便与follows后面的that呼应，使得句子结构更清晰；若和后者呼应，则在and then后面会紧跟一个介词by，以便和followed后面的by呼应。
3. called a snake修饰的是an empty sequence of diagonal edges.本回答被网友采纳

Answer 3