1 /(?<!a)c/i           "ac"  []
 2 /(?<!a)c/i           "aac" []
 3 /(?<!a)c/i           "Aac" []
 4 /(?<!a)c/i           "aAc" []
 5 /(?<!a)c/i           "AAc" []
 6 /(?<!a|b)c/i         "ac"  []
 7 /(?<!a|b)c/i         "aac" []
 8 /(?<!a|b)c/i         "Aac" []
 9 /(?<!a|b)c/i         "aAc" []
10 /(?<!a|b)c/i         "AAc" []
11 /(?<!aa)c/i          "ac"  ["c"]
12 /(?<!aa)c/i          "aac" []
13 /(?<!aa)c/i          "Aac" []
14 /(?<!aa)c/i          "aAc" []
15 /(?<!aa)c/i          "AAc" []
16 /(?<!aa|b)c/i        "ac"  ["c"]
17 /(?<!aa|b)c/i        "aac" []
18 /(?<!aa|b)c/i        "Aac" ["c"]
19 /(?<!aa|b)c/i        "aAc" ["c"]
20 /(?<!aa|b)c/i        "AAc" ["c"]
21 /(?<!(?:aa)|b)c/i    "ac"  ["c"]
22 /(?<!(?:aa)|b)c/i    "aac" []
23 /(?<!(?:aa)|b)c/i    "Aac" ["c"]
24 /(?<!(?:aa)|b)c/i    "aAc" ["c"]
25 /(?<!(?:aa)|b)c/i    "AAc" ["c"]
26 /(?<!b|aa)c/i        "ac"  ["c"]
27 /(?<!b|aa)c/i        "aac" []
28 /(?<!b|aa)c/i        "Aac" []
29 /(?<!b|aa)c/i        "aAc" []
30 /(?<!b|aa)c/i        "AAc" []
31 /(?<!b|(?:aa))c/i    "ac"  ["c"]
32 /(?<!b|(?:aa))c/i    "aac" []
33 /(?<!b|(?:aa))c/i    "Aac" []
34 /(?<!b|(?:aa))c/i    "aAc" []
35 /(?<!b|(?:aa))c/i    "AAc" []
36 /(?<!aa|bb)c/i       "ac"  ["c"]
37 /(?<!aa|bb)c/i       "aac" []
38 /(?<!aa|bb)c/i       "Aac" []
39 /(?<!aa|bb)c/i       "aAc" []
40 /(?<!aa|bb)c/i       "AAc" []