1. An automatic rule generation system, comprising: a hardware computer that executes a computer program that implements the automatic rule generation system, the computer program including a rule generation module, a rule relaxation module, a rule testing module, an information extraction module, and a candidate suggestion module, wherein: the rule generation module receives a sample and generates a rule from the sample; the rule relaxation module generates a relaxed rule from the rule; the rule testing module generates a reverse index from a corpus, applies the relaxed rule to the reverse index, and generates text segments; the information extraction module generates modified text segments from the relaxed rule and the text segments; and the candidate suggestion module performs a candidate generation process, wherein if the candidate generation process generates no candidates, the candidate suggestion module signals the rule relaxation module to generate a further relaxed rule to use as the relaxed rule.