起点 = (19.177275720164616, 6.743048010973931)
间距 = 1.18 (slider from 0.5 to 2, step 0.01)
位置 = Sequence(起点 - (0, k), k, 0, 20, 间距)

Tool: 坐标系
x最小、最大，y最小、最大，0.23
Input: m, n, q, p, a
Output: A, B, O, l1, l2, list3, list4, list5, list6, u, v

$\huge\textcolor{}{x}$

$\huge\textcolor{}{y}$

$\Large{O}$

u = Vector((m - 1, 0), (n + 1, 0))
l1 = Sequence(Segment[(k, 0), (k, a)], k, m, n)
A: (n + 1, 0)
list4 = Sequence(Text[k, Element[Sequence[(t - 0.15, 0), t, 1, n], k], true, true], k, 1, n)
list3 = Sequence(Text[k, Element[Sequence[(t - 0.5, 0), t, m, -1], k + abs(m) + 1], true, true], k, m, -1)
l2 = Sequence(Segment[(0, k), (a, k)], k, q, p)
list5 = Sequence(Text[k, Element[Sequence[(-0.9, t + 0.2), t, q, -1], k + abs(q) + 1], true, true], k, q, -1)
v = Vector((0, q - 1), (0, p + 1))
B: (0, p + 1)
list6 = Sequence(Text[k, Element[Sequence[(-0.6, t + 0.2), t, 1, p], k], true, true], k, 1, p)
O: B - (0, p + 1)