171 in ennealimmal notation

I propose that ennealimmal systems be notated using the nine nominals,
with symbols for 36/35, 49/48 = 50/49, 126/125, 225/224, and
32805/32768. If 36/35 is given the # symbol, then # is less than the b
of one nominal above, as in meantone, which seems neater. Below I give
notations for all the steps of 171, where the coefficient of n is the
nominal position, "a" gives the 36/35 sharp and flat, "b" 49/48, "c"
126/125, and "d" 225/224. Since 32805/32768 vanishes in 171, it does
not appear. The notations are chosen so as to minimize the number of
nominals, and in no case do we need more than two. Comments?

0: {0}
1: {d}
2: {c}
3: {c+d, b-c}
4: {2*c, b-d}
5: {b}
6: {b+d, a-d}
7: {a}
8: {a+d}
9: {n-2*b, a+c}
10: {2*b, n-a-c}
11: {n-a-d}
12: {n-a}
13: {n-a+d, n-b-d}
14: {n-b}
15: {n-b+d, n-2*c}
16: {n-b+c, n-c-d}
17: {n-c}
18: {n-d}
19: {n}
20: {n+d}
21: {n+c}
22: {n+b-c, n+c+d}
23: {n+b-d, n+2*c}
24: {n+b}
25: {n+b+d, n+a-d}
26: {n+a}
27: {n+a+d}
28: {n+a+c, 2*n-2*b}
29: {n+2*b, 2*n-a-c}
30: {2*n-a-d}
31: {2*n-a}
32: {2*n-a+d, 2*n-b-d}
33: {2*n-b}
34: {2*n-2*c, 2*n-b+d}
35: {2*n-b+c, 2*n-c-d}
36: {2*n-c}
37: {2*n-d}
38: {2*n}
39: {2*n+d}
40: {2*n+c}
41: {2*n+c+d, 2*n+b-c}
42: {2*n+2*c, 2*n+b-d}
43: {2*n+b}
44: {2*n+a-d, 2*n+b+d}
45: {2*n+a}
46: {2*n+a+d}
47: {2*n+a+c, 3*n-2*b}
48: {3*n-a-c, 2*n+2*b}
49: {3*n-a-d}
50: {3*n-a}
51: {3*n-b-d, 3*n-a+d}
52: {3*n-b}
53: {3*n-b+d, 3*n-2*c}
54: {3*n-b+c, 3*n-c-d}
55: {3*n-c}
56: {3*n-d}
57: {3*n}
58: {3*n+d}
59: {3*n+c}
60: {3*n+b-c, 3*n+c+d}
61: {3*n+2*c, 3*n+b-d}
62: {3*n+b}
63: {3*n+b+d, 3*n+a-d}
64: {3*n+a}
65: {3*n+a+d}
66: {4*n-2*b, 3*n+a+c}
67: {3*n+2*b, 4*n-a-c}
68: {4*n-a-d}
69: {4*n-a}
70: {4*n-a+d, 4*n-b-d}
71: {4*n-b}
72: {4*n-2*c, 4*n-b+d}
73: {4*n-b+c, 4*n-c-d}
74: {4*n-c}
75: {4*n-d}
76: {4*n}
77: {4*n+d}
78: {4*n+c}
79: {4*n+c+d, 4*n+b-c}
80: {4*n+2*c, 4*n+b-d}
81: {4*n+b}
82: {4*n+b+d, 4*n+a-d}
83: {4*n+a}
84: {4*n+a+d}
85: {4*n+a+c, 5*n-2*b}
86: {5*n-a-c, 4*n+2*b}
87: {5*n-a-d}
88: {5*n-a}
89: {5*n-a+d, 5*n-b-d}
90: {5*n-b}
91: {5*n-b+d, 5*n-2*c}
92: {5*n-b+c, 5*n-c-d}
93: {5*n-c}
94: {5*n-d}
95: {5*n}
96: {5*n+d}
97: {5*n+c}
98: {5*n+c+d, 5*n+b-c}
99: {5*n+b-d, 5*n+2*c}
100: {5*n+b}
101: {5*n+b+d, 5*n+a-d}
102: {5*n+a}
103: {5*n+a+d}
104: {5*n+a+c, 6*n-2*b}
105: {6*n-a-c, 5*n+2*b}
106: {6*n-a-d}
107: {6*n-a}
108: {6*n-b-d, 6*n-a+d}
109: {6*n-b}
110: {6*n-b+d, 6*n-2*c}
111: {6*n-b+c, 6*n-c-d}
112: {6*n-c}
113: {6*n-d}
114: {6*n}
115: {6*n+d}
116: {6*n+c}
117: {6*n+b-c, 6*n+c+d}
118: {6*n+2*c, 6*n+b-d}
119: {6*n+b}
120: {6*n+b+d, 6*n+a-d}
121: {6*n+a}
122: {6*n+a+d}
123: {7*n-2*b, 6*n+a+c}
124: {6*n+2*b, 7*n-a-c}
125: {7*n-a-d}
126: {7*n-a}
127: {7*n-a+d, 7*n-b-d}
128: {7*n-b}
129: {7*n-b+d, 7*n-2*c}
130: {7*n-c-d, 7*n-b+c}
131: {7*n-c}
132: {7*n-d}
133: {7*n}
134: {7*n+d}
135: {7*n+c}
136: {7*n+b-c, 7*n+c+d}
137: {7*n+b-d, 7*n+2*c}
138: {7*n+b}
139: {7*n+b+d, 7*n+a-d}
140: {7*n+a}
141: {7*n+a+d}
142: {8*n-2*b, 7*n+a+c}
143: {7*n+2*b, 8*n-a-c}
144: {8*n-a-d}
145: {8*n-a}
146: {8*n-a+d, 8*n-b-d}
147: {8*n-b}
148: {8*n-2*c, 8*n-b+d}
149: {8*n-c-d, 8*n-b+c}
150: {8*n-c}
151: {8*n-d}
152: {8*n}
153: {8*n+d}
154: {8*n+c}
155: {8*n+c+d, 8*n+b-c}
156: {8*n+2*c, 8*n+b-d}
157: {8*n+b}
158: {8*n+b+d, 8*n+a-d}
159: {8*n+a}
160: {8*n+a+d}
161: {8*n+a+c, 9*n-2*b}
162: {9*n-a-c, 8*n+2*b}
163: {9*n-a-d}
164: {9*n-a}
165: {9*n-a+d, 9*n-b-d}
166: {9*n-b}
167: {9*n-b+d, 9*n-2*c}
168: {9*n-b+c, 9*n-c-d}
169: {9*n-c}
170: {9*n-d}