Here is a list of proximities you may use:
Expression Locates
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power factor Power AND Factor within the same sentence
(default)
john marsha w/line John AND Marsha occurring on the same line
#>million pounds w/100 A quantity larger than 1000000 AND pounds
occurring within 100 characters of each other
john marsha w/[^()]{1,80} John AND Marsha within parenthesis or 80
characters whichever is first.