> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Character String hypothesis

> Properties of a Character String hypothesis in an Extraction Rules activity — character sets, regular-expression matching, and the recognized Text property.

If a regular expression is specified in the element properties, then the program looks for all character strings satisfying the expression. If no regular expression is specified, hypotheses are formulated using the set character sets.

When a hypothesis is formulated, all text objects overlapping with the search region horizontally are considered. Vertically, this object must be within the search region entirely. These text objects are then used to construct strings (left-to-right). In the constructed strings, character strings belonging to only one of the specified character sets are highlighted. Strings are also separated into fragments.

## Character String hypothesis properties

A formulated Character String hypothesis has the following type-specific properties (in addition to the general ones):

| Property | Description                                         |
| :------- | :-------------------------------------------------- |
| Text     | Specifies the character sequence in the hypothesis. |