- The added line is THIS COLOR.
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//[[Documentation]]
*Hyperlinks
*Hyperlinks and hypergraphs
LMNtal links represent point-to-point connection between atoms and form an ordinary graph. In some applications, however, we may want '''hyperlinks''', namely links that interconnect more than two atoms and form a '''hypergraph'''.
LMNtal links represent point-to-point connection between atoms and form an ordinary graph. In some applications, however, we may want '''hyperlinks''', namely links that interconnect more than two atoms. A graph structure with hyperlinks forms a '''(hierarchical) hypergraph'''.
LMNtal provides syntax and operations for hypergraphs, which will be described below. Currently, hyperlinks are supported by the slim runtime
in the ordinary (as opposed to non-deterministic) execution mode.
LMNtal provides syntax and operations for hypergraphs, which will be described below.
Currently, hyperlinks are supported by the '''SLIM''' runtime
running in the '''ordinary''' (as opposed to non-deterministic) execution mode.
**Creating a hyperlink
-A hyperlink is created by a "new" construct specified in a guard.
A hyperlink is created by a ''new'' construct specified in a guard.
hoge.
hoge :- new($h) | a($h), b($h).
*--> a(!1), b(!1).
--> a(!1), b(!1).
Each hyperlink is given a fresh private name, which will be printed as a "''!''" followed by a hexadecimal number.
-Each hyperlink is given a fresh private name, which will be printed as a "!" followed by a hexadecimal number.
**Type checking
-The type constraint "hlink($x)" checks if $x represents a hyperlink.
The type constraint ''hlink''($x) checks if $x represents a hyperlink.
main.
main :- new($x) | a($x).
a($x) :- hlink($x) | b($x).
*--> b(!1).
--> b(!1).
**Equality checking
-An occurrence of a hyperlink is regarded as a unary atom (with a special, private name). Therefore, the constructs == and \= can be used for comparing two hyperlinks, e.g.,
An occurrence of a hyperlink is regarded as a unary atom with a special, private name. Therefore, the constructs ''=='' and ''\='' can be used for comparing two hyperlinks, e.g.,
a($x), b($y) :- hlink($x), hlink($y), $x == $y | ok.
In addition, the above rule can be written as
The above rule can be written also as
a($x), b($x) :- ok.
**Fusing two hyperlinks
-Two hyperlinks can be fused into one using the "><" operator.
a(!1), b(!2).
Two hyperlinks can be fused into one using the "''><''" operator.
main.
main :- new($x), new($y) | a($x), b($y).
a($x), a($y) :- $x \= $y | a($x), b($y), $x >< $y.
If $x and $y represent different hyperlinks (i.e., have different hyperlink names), they will be merged into one; that is, they are made to have the same hyperlink name.
-If $x and $y represent different hyperlinks (i.e., have different hyperlink names), they will be merged into one; that is, they are made to have the same hyperlink name.
**Number of occurrences
-The "num" construct in a guard will return the number of occurrences of the specified hyperlink.
a(!1), b(!1).
The ''num'' construct in a guard will return the number of occurrences of the specified hyperlink.
main.
main :- new($x) | a($x), b($x).
a($h) :- $n = num($h) | number($n).
*--> b(!1), number(2).
--Another use
a(!1).
--> b(!1), number(2).
Another use:
main.
main :- new($x) | a($x).
a($h) :- $n = num($h), $n < 5 | a($h), a($h).
*--> a(!1), a(!1), a(!1), a(!1), a(!1).
--Yet another use
flag(!1), a(!1), a(!1), a(!1), a(!1).
--> a(!1), a(!1), a(!1), a(!1), a(!1).
Yet another use:
main :- new($x) | flag(!x), a(!x), a(!x), a(!x), a(!x).
a($h) :- hlink($h) | .
flag($h) :- $n = num($h), $n =:= 1 | ok.
*--> ok. // ok is created when all a(!1)'s are removed
--> ok. // ok is created when all a(!1)'s are removed
In this way, using hyperlinks, one can check the '''absence''' of a particular hyperlink.
---Thus, using hyperlinks, one can check the absence of a particular atom.
*How to use
**Compiling
**LaViT
Currently, programs with hyperlinks can be executed only under slim. To compile, both --slimcode and --hl (or --hl-opt) options need be specified, e.g.,
When you execute your program under LaViT (recommended), select the Option tab and turn on the following checkboxes:
- Slimcode Compile Option: ''--slimcode'' and ''--hl-opt''
- Slim Option: ''--hl''
lmntal --slimcode --hl hoge.lmn > hoge.il
Please see below for the details of those options.
-- --hl : uses hyperlinks.
//[[同名型付きプロセス文脈構文>http://www.ueda.info.waseda.ac.jp/~seiji/wiki/index.php?%B8%A6%B5%E6%C6%FC%BB%EF%A4%C8%A4%A6%A4%E1%A4%AD#r3fa6a93]]を許す
-- --hl-opt : uses hyperlinks and optimizes matching
// --- 以下は実装のこと
// --- 中間命令findproccxtが挿入される
// --- ガードに自動的にhlink制約を挿入ことで、ground対groundの構造比較をファンクタ対ファンクタで済ませるようにしている
// ---ちなみに同名型付きプロセス文脈は、処理系内部のコードではsameproccxtなどと呼称
**Compiling
***Executing
Currently, programs with hyperlinks can be executed only under SLIM. To compile them, both ''--slimcode'' and ''--hl'' (or ''--hl-opt'') options need be specified, e.g.,
lmntal --slimcode --hl hoge.lmn > hoge.il
- ''--hl'' : turn on hyperlinks.
- ''--hl-opt'' : turn on hyperlinks and optimize graph matching using hyperlink connection.
Specify --hl when running slim, e.g.,
**Execution
Specify ''--hl'' when running SLIM, e.g.,
slim --hl --show-hl hoge.il
- ''--hl'' : turn on hyperlinks
-- currently, this cannot be specified with ''-nd''.
- ''--show-hl'' : prints the details of hyperlinks.
-- Without this option, different occurrences of a hyperlink are printed with the same name.
-- With this option, each occurrence of a hyperlink is printed with its own ID. In addition, a table of hyperlink occurrences will be printed.
-- --hl : uses hyperlinks
--- currently, this cannot be specified with -nd
-- --show-hl : prints the details of hyperlinks
--- Without this option, different occurrences of a hyperlink are printed with the same name.
--- With this option, each occurrence of a hyperlink is printed with its own ID. In addition, a table of hyperlink occurrences will be printed.
![[PukiWiki]](lmntal_220x80.png "[PukiWiki]")
