Why doesn't this regex work? (Solved!)

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105 106 107 108 109 110 111 112 113
1115 1116 1117 1118 1119 1120 1121 1122 1123
12345 12346 12347 12348 12349 12350 12351 12353

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105 106 107 108 109
110 111 112 113
...
1120 1121 1122 1123
12345 12346 12347 12348 12349 
12350 12351 12353

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#! perl -slw
use strict;
...
105 106 107 108 109 110 111 112 113
1115 1116 1117 1118 1119 1120 1121 1122 1123
12345 12346 12347 12348 12349 12350 12351 12353

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perl -ple"s[(?<=\s(\d{3})\d\d)\s(?=(\d{3})\d\d\s)][$1+1==$2 ? qq[\n] :
+ ' ' ]ge" in > out

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