Information Label Adjudication
When two pieces of data with separate information labels (e.g., objects, files, part of a window's contents) are merged or combined, the system automatically adjudicates the combination of the two information labels, determining the single information label that properly represents the merged data. This process of adjudicating two information labels is also called combining the labels or floating one label with the second one. The values assigned to classifications and the internal compartment and marking bit representations assigned to information label words determine how the system will adjudicate information labels.
When the system adjudicates the classifications from two information labels, the resulting classification is always the classification with the greater internal integer value. Since all classifications by definition form a strict hierarchy, specifying integer values for classifications that represent the hierarchy, with the most sensitive classifications having the highest values and the least sensitive classifications having the lowest values, will assure the proper adjudication of classifications.
Considerations for the proper adjudication of words is much more complicated. The system adjudicates information label compartment and marking bits by performing a bitwise logical “or” of the bit strings, as shown in Table 1–2.
Table 1–2 Information Label Bit String Combination Example| Bit Strings | |||
| Compartments | Markings | ||
| Information Label 1 (IL1) | 10100000 | 00001111 | |
| Information Label 2 (IL2) | 11010001 | 11000000 | |
| Adjudication (IL1 + IL2) | 11110001 | 11001111 | |
Proper adjudication is assured by defining the bit representation of each information label word such that the desired properties are enforced when the words are combined via logical “or.” Table 1–3` shows a number of different possibilities for the adjudication of the combination of words. In this and following figures, (NULL) is used to indicate the absence of any word.
As mentioned above, there are two basic types of words: normal and inverse. Additionally, words can optionally appear in a hierarchy with other words. To support these different types of words, the encodings allow for a great deal of flexibility in the association of human-readable word names with internal bit patterns. Rather than simply assigning names to bits, the encodings allow word names to be associated with specific bit patterns. These bit patterns can include compartment bits, marking bits, or both. The examples shown in Table 1–3 are expanded below, showing how the internal encodings of the words implement the desired adjudication of normal words, inverse words, words in hierarchies, composite words, and a more complex example.
In each example, the relevant bit values associated with words are shown as 1s and 0s. Irrelevant bit positions are denoted with –s. Each example below shows two labels and their combination, in both human-readable and internal forms. (NULL) is used to indicate a label containing no words. The bits shown in the examples below could be compartment bits, marking bits, or a combination of both. From the standpoint of label adjudication, there is no difference between compartment bits and marking bits.
Table 1–3 Label Adjudication Examples
Normal Words
Normal words are associated with internal bit patterns consisting only of 1s. Normal words can have one or more 1 bits associated with them. The example below is for the simplest and most common case, where a single bit is associated with a word. When such a word is combined with a label containing no words, the resulting label contains just the word.
| Word1 | 1––––––– |
| (NULL) | –––––––– |
| Word1 | 1––––––– |
In the following example, two normal words each associated with different 1 bits are combined. The resulting label contains both words.
| Word1 | 1––––––– |
| Word3 | ––1––––– |
| Word1 Word3 | 1–1––––– |
Inverse Words
Inverse words are associated with internal bit patterns containing at least one inverse bit. An inverse bit is a bit whose 0 value is associated with the presence of a word and whose value is 1 unless the word is present in the label. Inverse words can have one or more bits associated with them. The example below is for the simplest and most common case, where a single 0 bit is associated with a word. When a bit is used inversely, its value in a NULL label must be 1. When such a word is combined with a label containing no words, the resulting label does not contain the word.
| Word2 | –0–––––– |
| (NULL) | –1–––––– |
| (NULL) | –1–––––– |
In the following example, two inverse words each associated with different inverse (0) bits are combined. The resulting label contains neither of the words.
| Word2 | –0–––1–– |
| Word6 | –1–––0–– |
| (NULL) | –1–––1–– |
In the example below, two labels containing the above inverse words are combined. Only the inverse word that appears in both labels appears in the resulting combination.
| Word2 | –0–––1–– |
| Word2 Word6 | –0–––0–– |
| Word2 | –0–––1–– |
Hierarchies of Words
Two words form a hierarchy if their associated relevant bits form a hierarchy (i.e., if one set of bits includes the other). Words in hierarchies can be either normal or inverse words. The following example is the simplest case of a hierarchy of two normal words. In this example, as should be evident from the bits, Word5 is hierarchically above Word4. Therefore, when the two words are combined, the result is the higher of the two words, Word5. Two words in the same hierarchy can never appear together in a label.
| Word5 | –––11––– |
| Word4 | –––1–––– |
| Word5 | –––11––– |
Composite Words
This example is very similar to the above example involving Word1 and Word3, with the difference being that this example contains a third word that is the composite of the other two. Word9 is a composite word whose meaning is “the combination of Word7 and Word8.”Such a composite word might be used rather than having the individual words combined to appear in the combination label. In this example, the composite word and the words it combines are a special case of word hierarchies. Therefore, the composite word cannot appear in the same label with either of the words of which it is composite.
| Word7 | ––––––1– |
| Word8 | –––––––1 |
| Word9 | ––––––11 |
Non-Hierarchical Composite Words
It is possible to form a composite word without a hierarchy involved. Non-hierarchical composite words are possible for words that have more than one bit associated. In the following example, Word12 is a composite of Word10 and Word11, but has no hierarchical relationship with either word. Therefore, Word12 can appear in the same label with Word10 and Word11. When Word10 and Word11 are combined the resulting label contains all three words.
| Word10 | 1–––––1– |
| Word11 | –1–––––1 |
| Word12 | ––––––11 |
A Complex Example
Both normal and inverse words can appear in hierarchies. The example below shows a complex combination of an inverse word and hierarchies. Word13 is a word whose internal representation consists of one normal (1) bit and one inverse (0) bit. Because one of the bits is inverse, its value in any label not containing Word13 will be 1, as shown on the second line of the example. Word14 is a normal word in a hierarchy above Word13. The interesting result of this particular combination of hierarchies and inverse bits is that if Word13 is combined with any label that does not contain Word13, the resulting label contains Word14 instead of Word13.
| Word13 | 10–––––– |
| (any label | |
| without Word13) | –1–––––– |
| Word14 | 11–––––– |
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