query: Regex doesn't detect symbol
positive_passages.docid: 1388
positive_passages.text: Learning Regular Expressions
negative_passages.docid: 35292
negative_passages.text: No matches with c++11 regex
negative_passages.docid: 106655
negative_passages.text: Grep: The asterisk (*) doesn't always work
negative_passages.docid: 152030
negative_passages.text: How to match a pattern with a pattern?
negative_passages.docid: 26682
negative_passages.text: PHP regular expressions: No ending delimiter '^' found in
negative_passages.docid: 21107
negative_passages.text: Search using symbols is broken
negative_passages.docid: 28280
negative_passages.text: Python and regular expression with Unicode
negative_passages.docid: 61052
negative_passages.text: Regex to match attributes in HTML?
negative_passages.docid: 131388
negative_passages.text: using regex for math expressions in java?
negative_passages.docid: 110372
negative_passages.text: Unicode Regex; Invalid XML characters
negative_passages.docid: 1685
negative_passages.text: Why does this Java regex cause "illegal escape character" errors?
negative_passages.docid: 10125
negative_passages.text: How does this regular expression work?
negative_passages.docid: 45334
negative_passages.text: How can I debug a regular expression in Python?
negative_passages.docid: 13586
negative_passages.text: Why do regex constructors need to be double escaped?
negative_passages.docid: 41380
negative_passages.text: How to check if a given Regex is valid?
negative_passages.docid: 52449
negative_passages.text: Java RegEx meta character (.) and ordinary dot?
negative_passages.docid: 120978
negative_passages.text: Difference between regex [A-z] and [a-zA-Z]