Actually this brings me to another question along the same lines which is...if I wanted to (as I do) check for records where there may be a keyword before "train times" that may mean the record is to be rejected i.e. a negative lookbehind assertion I assume
e.g. 
help train times from xyz
load train times including xyz
help train times including xyz
book train times at 1234

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I need to reject records where the word immediately before "train times" is help. If help is used in the text it would always be the first word in the record. So only record two & four in my example would be printed. I tried doing this 
print if /(?<!help).*train times/; #doesn't work
print if /^(!help).*train times/; # doesn't work either

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Based on other comments I've read it seems that the use of negative lookbehind assertion should be discouraged but I'm not sure how to handle this without doing an assertion ?

In reply to Re^2: negate pattern match by Anonymous Monk
in thread negate pattern match by Anonymous Monk

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