Grammar Description Language. A subset of the Lada language

    The Lada system has its own means of describing grammar, so this is the notation used in the text, a brief description of which is given below.

    1. A concept is defined by the Determination operator, followed by the name of the concept being defined and then defining the sequence of concepts in brackets.
    2. The name of the concept being defined can contain no more than forty letters, or any characters enclosed in the name brackets "" ". For more details, see the naming rules (Section 1).
    3. If you need to define several concepts at once, they are enclosed in braces (or parentheses separated by commas) after the Determination operator Section 2.1 Objects enclosed in parentheses will be called a group.
    4. The sequence of characters directly involved in the analysis is highlighted with text brackets "" "and" "".
    5. Objects or groups separated by a “|” mean the execution of one of these objects or groups. Operation "Or."
    6. The sequence of definitions in brackets (group), and the sign "|" after the opening bracket (without space) indicates the selection of one option from this sequence. The Ili Group.
    7. The sign “¬” in front of a concept (or group of concepts) means that anything except this concept (or group of concepts) is permissible in the analysis. Operation No.
    8. The sequence of definitions in parentheses (group), and the sign “¬” after the opening parenthesis (without a space) indicates that there is no match with any variant of this sequence. No group.
    9. The superscript value, after the closing bracket, determines the maximum number of permissible repetitions of concepts combined by the group that this bracket closes.
    10. The subscript value after the group of concepts indicates the minimum number of occurrences of this concept in the definition. The value 0 allows the absence of a group of concepts in the analysis.


    1. Determination Digit {0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9}
    2. Determination Letter (| A, B, ..., I)
    3. Determination
    Word {Letter} 140
    Name {"" "{¬" ""} 128 "" "}

    These rules are used to program grammars. For use in the text, we will omit the Determination operator, and use the “=” sign after the concept being defined. And recall once again that the presence of commas separating objects is necessary only when grouping with parentheses. Objects separated by the infix operation "Or" are considered one object and do not need to be separated by commas even when using parentheses.


    Digit = (| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)

    In this form, this is similar to the Backus-Naur form and is more easily perceived.

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