Documentation for POS Intellect 5.4. Documentation for other versions of Intellect is available too.

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For example, there are two strings:

abcd12345efg 
fghi56789qwe

Condition: Find parts in strings which contain four latin letters and then 5 digits.

How to describe a symbol coincident with some Latin letter (a symbol sorting is in user for it: [a-z] (don't pay attention to capitals)), and a symbol of coincident with a digit: [0-9] was described in the previous section.

It's required to find strings with four letters at first and 5 digits straight after them.

It's allowable to write: [a-z][a-z][a-z][a-z][0-9][0-9][0-9][0-9][0-9] 

Such form of search condition will work. One symbol of search condition is described by symbol sorting. Such construction is too massive. It's recommended to use quantifiers in such cases. Quantifier determines number of symbols in a search condition. So the search condition will be simplified be quantifiers: [a-z]{4}[0-9]{5}

Number of symbols described in symbol sorting and going one after another in a string is specified in curved brackets.

So 5 digits are going after 4 Latin letters. Each symbol sorting described only one symbol, number of similar sequential symbols are described by quantifiers.

This specifying of symbol numbers in a search condition is not unique. Quantifiers can be different: [a-z]{1,3} means that from one to three Latin letters can go one after another. [a-z]{2,} means that minimum two Latin letters can go one after another.

Quantifier in curved brackets is not unique way to set number of symbols going one after another. [a-z]* means that any number of Latin letters can go one after another, like [a-z]{0,}. [a-z]+ means that at least one Latin letter can go one after another, but maximal number is not specified, like [a-z]{1,}. [a-z]? means that number of Latin letters is not more than 1, letter also can be missed, like [a-z]{0,1}.

Condition search of similarities which is described by nonspecial symbol is a literal.

Some of quantifiers given above can be applied to literals. 

If the abcd{1,4}efg condition search will be applied for abcefg string, the similarities won't be found because a quantifier {1,4} means that from one to four digits "d" will be after abc and before efg.

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