October 1, 1979 KEYWORD STRINGS
BOOLEAN REQUEST FORMAT
14.2 Boolean Request Format ___________________________
The rules for retrieving Blocks (via BTCONTINUOUS, BTDISCRETE)
and for matching Keywords (SKANNOTATION, SKDISPLAY, SKJUMP) are
the same. They are as follows: With either type of request, a
Keyword in the request will match either a Keyword or the value
part of an Attribute-value pair in the file; e.g., a request for
the Keyword "Irving_Berlin" would be satisfied by either
Attribute-value pair shown in Appendix C.1. An attribute-value
pair will match only another attribute-value pair. In this way
the user can select only that music for which Berlin wrote the
lyrics with no regard to the composer. If the "keys" (Keywords or
attribute-value pairs) match, then Weights are compared (see
Appendix C.1 for a description of Weights). If the request or the
Keyword in the file is unweighted the match is successful. If both
are weighted then the Keyword in the file must have a Weight equal
to or higher than the Keyword in the request in order to satisfy
the request. Boolean combinations of requested Keywords are
satisfied using standard interpretations of the logical operators
"¬" (not), "&" (and), and "" (or), in order of descending
may precedence. The precedence ___ be changed by the use of
parentheses, and is recommended for clarity (see the examples
below).
EXAMPLES ________
bt/Keyword1&key2key3 _____________________
retrieves all Blocks with both Keyword1 and key2, as well as
all Blocks with key3
bt/Keyword1&(key2key3) _______________________
retrieves all Blocks with both Keyword1 and key2, and all
Blocks with both Keyword1 and key3
bt/¬key1 ________
is invalid ___________ since it requests all Blocks which do not have
key1 and it is not permitted to enumerate all Keyworded
Blocks (possibly hundreds).
skd/all& imlac& double ______________________
"turns off" all Blocks which do not have th display keywords
"all." Furthermore, any Block which has either of the
display Keywords "imlac" or "double" is also "turned off".
270 -- Appendix C Release 9.1 FRESS Resource Manual
BOOLEAN REQUEST FORMAT
14.2 Boolean Request Format ___________________________
The rules for retrieving Blocks (via BTCONTINUOUS, BTDISCRETE)
and for matching Keywords (SKANNOTATION, SKDISPLAY, SKJUMP) are
the same. They are as follows: With either type of request, a
Keyword in the request will match either a Keyword or the value
part of an Attribute-value pair in the file; e.g., a request for
the Keyword "Irving_Berlin" would be satisfied by either
Attribute-value pair shown in Appendix C.1. An attribute-value
pair will match only another attribute-value pair. In this way
the user can select only that music for which Berlin wrote the
lyrics with no regard to the composer. If the "keys" (Keywords or
attribute-value pairs) match, then Weights are compared (see
Appendix C.1 for a description of Weights). If the request or the
Keyword in the file is unweighted the match is successful. If both
are weighted then the Keyword in the file must have a Weight equal
to or higher than the Keyword in the request in order to satisfy
the request. Boolean combinations of requested Keywords are
satisfied using standard interpretations of the logical operators
"¬" (not), "&" (and), and "" (or), in order of descending
may precedence. The precedence ___ be changed by the use of
parentheses, and is recommended for clarity (see the examples
below).
EXAMPLES ________
bt/Keyword1&key2key3 _____________________
retrieves all Blocks with both Keyword1 and key2, as well as
all Blocks with key3
bt/Keyword1&(key2key3) _______________________
retrieves all Blocks with both Keyword1 and key2, and all
Blocks with both Keyword1 and key3
bt/¬key1 ________
is invalid ___________ since it requests all Blocks which do not have
key1 and it is not permitted to enumerate all Keyworded
Blocks (possibly hundreds).
skd/all& imlac& double ______________________
"turns off" all Blocks which do not have th display keywords
"all." Furthermore, any Block which has either of the
display Keywords "imlac" or "double" is also "turned off".
270 -- Appendix C Release 9.1 FRESS Resource Manual
