From: http://www.daimi.au.dk/pn2000/Interchange/papers/det_02.ps.gz

Textual Interchange Format for High-level Petri Nets.

Appendix 

A Full DTD for Design/CPN 3.1 

1 <!-- DTD for Textual Interchange Format for Design/CPN ver. 3.1 --> 
2 
3 <!-- Base element --> 
4 <!DOCTYPE cpn [ 
5 
6 <!-- Possible shapes for obejcts: rbox is a rounded box --> 
7 <!ENTITY % shape "(box | ellipse | poly | line | label | wedge | rbox 
8 | seg-conn)"> 
9 
10 <!-- Legal attributes for objects --> 
11 <!ENTITY % atts "%shape;? & posattr? & fillattr? & lineattr? & 
12 textattr? & flags? & layering?"> 
13 
14 <!-- Line types: --> 
15 <!ENTITY % lintyps "(Solid | Dashed | DotDash | GroupInd | 
16 FlashInd | None | Null | Dotted)"> 
17 
18 <!-- Colours. These colours corresponds to the standard colours of 
19 HTML: --> 
20 <!-- 
21 Name and RGB value: 
22 Black = #000000 Green = #008000 
23 Silver = #C0C0C0 Lime = #00FF00 
24 Gray = #808080 Olive = #808000 
25 White = #FFFFFF Yellow = #FFFF00 
26 Maroon = #800000 Navy = #000080 
27 Red = #FF0000 Blue = #0000FF 
28 Purple = #800080 Teal = #008080 
29 Fuchsia= #FF00FF Aqua = #00FFFF 
30 --> 
31 <!ENTITY % cols "(Black | Maroon | Gray | Olive | 
32 Purple | Silver | Red | Teal | 
33 Navy | Fucia | Blue | Aqua | 
34 Green | Lime | Yellow | White)"> 
35 
36 <!-- The possible orientations of an arc: 
37 BOTHDIR = Bidirectional arc: O<->[] 
38 NODIR = Arc without arrows: O-[] 
39 PtoT = Arc from Place to Transition: 0->[] 
40 TtoP = Arc from Transition to Place: []->O 
41 --> 
42 <!ENTITY % arcors "(BOTHDIR | NODIR | PtoT | TtoP)"> 
43 
44 <!-- Possible types of fusion sets: 
45 Global = Global fusion set. 
46 Page = Page Fusion set.
47 Instance = Instance Fusion Set --> 
48 <!ENTITY % fustyps "(Global | Page | Instance)"> 
49 
50 <!-- Possible orientations of an auxiliary connector: --> 
51 <!-- BOTHDIR = Bidirectional connector. 
52 NODIR = Nondirectional connector. 
53 1to2 = Connector from object1 to object2 
54 2to1 = Connector from object2 to object1 --> 
55 <!ENTITY % orients "(BOTHDIR | NODIR | 1to2 | 2to1)"> 
56 
57 <!-- Possible fill patterns for objects --> 
58 <!ENTITY % pats "(None | Solid | AlmostSolid | InverseHeavyDotted | 
59 Chessboard | InverseOrderedDotted | 
60 NarrowVertical | FilledDiagonals 
61 | WideVertical | Speckled | RandomDotted | 
62 NarrowGrid | Bricks | SparselyDotted | 
63 ShortDiagonals | Lightbubbles | PieTop | 
64 Buttercups | Waffles | 
65 LightDotted | MediumDotted | LightGray | 
66 OrderedDotted | NarrowHorizontal | 
67 NarrowDiagonal | WideHorizontal | WideDiagonal 
68 | DottedBoxes | WideGrid | DiagonalBricks | 
69 Holiday | Carrots | DiagonalScales | 
70 RoundScales | Mountains | HeavyBubbles | 
71 Diamonds)"> 
72 
73 <!-- Possible font names. --> 
74 <!ENTITY % fonts "(Chicago | Courier | Geneva | Helvetica | Monaco 
75 | Times | Symbol)"> 
76 
77 <!-- The justification of text (left aligned, centered or right 
78 aligned. --> 
79 <!ENTITY % justs "(Left | Centered | Right)"> 
80 
81 <!-- Possible porttypes: --> 
82 <!-- In = Input Port. 
83 Out = Output Port. 
84 InOut = Input/Output Port 
85 General = General Port --> 
86 <!ENTITY % prttyps "(In | Out | InOut | General)"> 
87 
88 <!-- Possible layering of object --> 
89 <!-- Copy --> 
90 <!-- IOR = Inclusive OR --> 
91 <!-- XOR = Exclusive OR --> 
92 <!-- INV = Inverse the objects covered --> 
93 <!ENTITY % laytyps "(Copy | IOR | XOR | INV)"> 
94 
95 <!-- Possible attributes of objects: --> 
96 <!--
97 posattr = Position attributes 
98 fillattr = Fill Attributes 
99 lineattr = Line Attributes 
100 textattr = Text Attributes 
101 flags = Various flags (see definition of flags) 
102 layering = Layering logic of object --> 
103 <!ENTITY % objatts "posattr | fillattr | lineattr | textattr | 
104 flags | layering"> 
105 
106 <!-- Objects legal within a page: --> 
107 <!-- place = Place 
108 trans = Transition 
109 tempdecl = Temporary Declaration Node 
110 globdecl = Global Declaration Node 
111 locdecl = Local Declaration Node 
112 aux = Auxiliary Object 
113 aux-conn = Auxiliary Connector --> 
114 <!ENTITY % pageobs "place | trans | tempdecl | globdecl | locdecl 
115 | arc | aux | aux-conn"> 
116 
117 <!-- Blocks legal within a place block: --> 
118 <!-- name = Name block. 
119 type = Type declaration block. 
120 initmark = Initial marking block. 
121 aux-endp = Auxiliary endpoint block 
122 aux-std = Auxiliary region block 
123 fus-key = Fusion key region block 
124 portkreg = Port key region block 
125 mark-key = Marking key region block --> 
126 
127 <!ENTITY % placeob "name | type | initmark | aux-endp | aux-std | 
128 fus-key | portkreg | mark-key"> 
129 
130 <!-- Blocks legal within a place block: --> 
131 <!-- name = Name block 
132 cond = Condition block 
133 code-key = Code key region block 
134 log-key = Log key region block 
135 time = Time block 
136 aux-endp = Auxiliary endpoint region block 
137 hier-key = Hierarchy key region block. 
138 aux-enab = Enabling region. --> 
139 <!ENTITY % transob "name | cond | code-key | log-key | time | 
140 aux-endp | hier-key | aux-enab"> 
141 
142 <!-- Elements recognised on outermost level of a cpn-document: 
143 Information about generator tool. 
144 One or more ordinary pages. 
145 Zero or one hierarchy page --> 
146 <!ELEMENT cpn O O ((page)* & hierpage? & generator?)>
147 
148 
149 <!-- Text blocks are recognised to contain Character Data --> 
150 <!ELEMENT text - - CDATA> 
151 
152 <!-- Elements and attributes recognised within a page --> 
153 <!ELEMENT page - - (text? & (%pageobs; | %shape; | pageattr | fillattr | 
154 lineattr | posattr | winattr | modeattr | mult)*)> 
155 <!ATTLIST page id ID #IMPLIED> 
156 
157 <!-- Elements and attributes recognised within a place --> 
158 <!ELEMENT place - - (text? & (%placeob; | %shape; | %objatts; | port)*)> 
159 <!ATTLIST place id ID #IMPLIED> 
160 
161 <!-- Elements and attributes recognised within a name block --> 
162 <!ELEMENT name - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
163 <!ATTLIST name id ID #IMPLIED> 
164 
165 <!-- Elements and attributes recognised within a type block --> 
166 <!ELEMENT type - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
167 <!ATTLIST type id ID #IMPLIED> 
168 
169 <!-- Elements and attributes recognised within an initial marking block --> 
170 <!ELEMENT initmark - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
171 <!ATTLIST initmark id ID #IMPLIED> 
172 
173 <!-- Elements and attributes recognised within a transition block --> 
174 <!ELEMENT trans - - (text? & (%transob; | %shape; | %objatts; | modeattr | 
175 subst)*)> 
176 <!ATTLIST trans id ID #IMPLIED> 
177 
178 <!-- Elements and attributes recognised within a condition block --> 
179 <!ELEMENT cond - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
180 <!ATTLIST cond id ID #IMPLIED> 
181 
182 <!-- Elements and attributes recognised within a code key region block --> 
183 <!ELEMENT code-key - - (text? & (aux-std | code | %shape; | %objatts; 
184 | regattr)*)> 
185 <!ATTLIST code-key id ID #IMPLIED> 
186 
187 <!-- Elements and attributes recognised within a code region block --> 
188 <!ELEMENT code - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
189 <!ATTLIST code id ID #IMPLIED> 
190 
191 <!-- Elements and attributes recognised within a log key region block --> 
192 <!ELEMENT log-key - - (text? & (aux-std | log | %shape; | %objatts; 
193 | regattr)*)> 
194 <!ATTLIST log-key id ID #IMPLIED> 
195 
196 <!-- Elements and attributes recognised within a log region block -->
197 <!ELEMENT log - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
198 <!ATTLIST log id ID #IMPLIED> 
199 
200 <!-- Elements and attributes recognised within a time block --> 
201 <!ELEMENT time - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
202 <!ATTLIST time id ID #IMPLIED> 
203 
204 <!-- Elements and attributes recognised within a hierarchy key region block --> 
205 <!ELEMENT hier-key - - (text? & (aux-std | hierarch | %shape; | 
206 %objatts; | regattr)*)> 
207 <!ATTLIST hier-key id ID #IMPLIED> 
208 
209 <!-- Elements and attributes recognised within a hierarchy region block --> 
210 <!ELEMENT hierarch - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
211 <!ATTLIST hierarch id ID #IMPLIED> 
212 
213 <!-- Elements and attributes recognised within a fusion key region block --> 
214 <!ELEMENT fus-key - - (text? & (aux-std | fusion | %shape; | 
215 %objatts; | regattr)*)> 
216 <!ATTLIST fus-key id ID #IMPLIED> 
217 
218 <!-- Elements and attributes recognised within a fusion region block --> 
219 <!ELEMENT fusion - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
220 <!ATTLIST fusion id ID #IMPLIED 
221 type %fustyps; #IMPLIED 
222 > 
223 
224 <!-- Elements and attributes recognised within an arc block --> 
225 <!ELEMENT arc - - (text? & (annot | aux-std | %shape; | lineattr | 
226 placeend | transend | textattr | flags | connattr | 
227 fillattr | layering)*)> 
228 <!ATTLIST arc id ID #IMPLIED 
229 orientation %arcors; #IMPLIED 
230 > 
231 
232 <!-- Elements and attributes recognised within an arc annotation block --> 
233 <!ELEMENT annot - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
234 <!ATTLIST annot id ID #IMPLIED> 
235 
236 <!-- Elements and attributes recognised within an local declaration block --> 
237 <!ELEMENT locdecl - - (text? & (aux-endp | aux-std | %shape; | %objatts;)*)> 
238 <!ATTLIST locdecl id ID #IMPLIED> 
239 
240 <!-- Elements and attributes recognised within a temporary declaration block --> 
241 <!ELEMENT tempdecl - - (text? & (aux-endp | aux-std | %shape; | %objatts;)*)> 
242 <!ATTLIST tempdecl id ID #IMPLIED> 
243 
244 <!-- Elements and attributes recognised within a global declaration block --> 
245 <!ELEMENT globdecl - - (text? & (aux-endp | aux-std | %shape; | %objatts;)*)> 
246 <!ATTLIST globdecl id ID #IMPLIED>
247 
248 <!-- Elements and attributes recognised within an auxiliary object block --> 
249 <!ELEMENT aux - - (text? & (aux-endp | aux-std | %shape; | %objatts;)*)> 
250 <!ATTLIST aux id ID #IMPLIED> 
251 
252 <!-- Elements and attributes recognised within an auxiliary connector block --> 
253 <!ELEMENT aux-conn - - (text? & (aux-std | %shape; | lineattr | node1 | 
254 node2 | textattr | flags | connattr | fillattr | 
255 layering)*)> 
256 <!ATTLIST aux-conn id ID #IMPLIED 
257 orient %orients; #IMPLIED 
258 > 
259 
260 <!-- Elements and attributes recognised within an auxiliary standard region 
261 block --> 
262 <!ELEMENT aux-std - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
263 <!ATTLIST aux-std id ID #IMPLIED> 
264 
265 <!-- Elements and attributes recognised within an auxiliary endpoint region 
266 block --> 
267 <!ELEMENT aux-endp - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
268 <!ATTLIST aux-endp id ID #IMPLIED> 
269 
270 <!-- Elements and attributes recognised within a port key region block --> 
271 <!ELEMENT portkreg - - (text? & (aux-std | portreg | %shape; | 
272 %objatts; | regattr)*)> 
273 <!ATTLIST portkreg id ID #IMPLIED> 
274 
275 <!-- Elements and attributes recognised within a port region block --> 
276 <!ELEMENT portreg - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
277 <!ATTLIST portreg id ID #IMPLIED> 
278 
279 <!-- Elements and attributes recognised within a marking key region block --> 
280 <!ELEMENT mark-key - - (text? & (aux-std | mark | %shape; | %objatts; 
281 | regattr)*)> 
282 <!ATTLIST mark-key id ID #IMPLIED> 
283 
284 <!-- Elements and attributes recognised within a marking region block --> 
285 <!ELEMENT mark - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
286 <!ATTLIST mark id ID #IMPLIED> 
287 
288 <!-- Elements and attributes recognised within an auxiliary enabling 
289 region block --> 
290 <!ELEMENT aux-enab - - (text? & (%shape; | %objatts; | regattr)*)> 
291 <!ATTLIST aux-enab id ID #IMPLIED> 
292 
293 <!-- Elements and attributes recognised within a hierarchy page block. --> 
294 <!ELEMENT hierpage - - (text? & (aux | aux-conn | pagenode | substcon 
295 | %shape; | pageattr | fillattr | lineattr | 
296 posattr | winattr)*)>
297 <!ATTLIST hierpage id ID #IMPLIED> 
298 
299 <!-- Elements and attributes recognised within an hierarchy page node block. --> 
300 <!ELEMENT pagenode - - (text? & (aux-std | pgmodkey | %shape; | %objatts;)*)> 
301 <!ATTLIST pagenode id ID #IMPLIED 
302 pageref IDREF #IMPLIED> 
303 
304 <!-- Elements and attributes recognised within a page mode key region 
305 block --> 
306 <!ELEMENT pgmodkey - - (text? & (pagemode | aux-std | %shape; | 
307 %objatts; | regattr)*)> 
308 <!ATTLIST pgmodkey id ID #IMPLIED> 
309 
310 <!-- Elements and attributes recognised within a page mode region block --> 
311 <!ELEMENT pagemode - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
312 <!ATTLIST pagemode id ID #IMPLIED> 
313 
314 <!-- Elements and attributes recognised within a substitution connector block --> 
315 <!ELEMENT substcon - - (text? & (aux-std | substtag | %shape; | lineattr | 
316 sup-page | sub-page | textattr | flags | connattr | 
317 fillattr | layering)*)> 
318 <!ATTLIST substcon id ID #IMPLIED 
319 orient %orients; #IMPLIED 
320 > 
321 
322 <!-- Elements and attributes recognised within a substitution tag block --> 
323 <!ELEMENT substtag - - (text? & (aux-std | %shape; | %objatts; | regattr)*)> 
324 <!ATTLIST substtag id ID #IMPLIED 
325 transref IDREF #IMPLIED 
326 > 
327 
328 <!-- Name and version of tool which generated file --> 
329 <!ELEMENT generator - O EMPTY> 
330 <!ATTLIST generator tool CDATA 
331 version CDATA> 
332 
333 <!-- Position attributes: --> 
334 <!-- x : x coordinate in mm 
335 y: x coordinate in mm 
336 
337 SGML doesn't allow a definition of numbers which might be negative, 
338 hence the use of CDATA as type for the coordinates. 
339 
340 The coordinate system looks like this: 
341 ^ 
342 | y 
343 | 
344 | 
345 | x 
346 ______________\
347 | / 
348 | 
349 | 
350 | 
351 --> 
352 
353 <!ELEMENT posattr - O EMPTY> 
354 <!ATTLIST posattr x CDATA #IMPLIED 
355 y CDATA #IMPLIED 
356 > 
357 
358 <!-- Definition of various shapes. 
359 
360 The attributes: 
361 h = height (in mm) 
362 w = width (in mm) 
363 
364 These are declared as CDATA since SGML has no way of defining real 
365 numbers. 
366 
367 Decimal seperator is '.'. 
368 
369 curv = curvature (0-360) 
370 stangle = start angle (0-360) 
371 endangle = end angle (0-360) 
372 points = sequence of points "(x1,y1)(x2,y2)...(xn,yn)" 
373 --> 
374 
375 
376 <!ELEMENT box - O EMPTY> 
377 <!ATTLIST box h CDATA #IMPLIED 
378 w CDATA #IMPLIED 
379 > 
380 
381 <!ELEMENT ellipse - O EMPTY> 
382 <!ATTLIST ellipse h CDATA #IMPLIED 
383 w CDATA #IMPLIED 
384 > 
385 
386 <!ELEMENT poly - O EMPTY> 
387 <!ATTLIST poly points CDATA #IMPLIED> 
388 
389 <!ELEMENT line - O EMPTY> 
390 <!ATTLIST line points CDATA #IMPLIED> 
391 
392 <!ELEMENT label - O EMPTY> 
393 
394 <!ELEMENT wedge - O EMPTY> 
395 <!ATTLIST wedge h CDATA #IMPLIED 
396 w CDATA #IMPLIED
397 stangle NUMBER #IMPLIED 
398 endangle NUMBER #IMPLIED 
399 > 
400 
401 <!ELEMENT rbox - O EMPTY> 
402 <!ATTLIST rbox h CDATA #IMPLIED 
403 w CDATA #IMPLIED 
404 curv NUMBER #IMPLIED 
405 > 
406 
407 <!ELEMENT seg-conn - O EMPTY> 
408 <!ATTLIST seg-conn curv NUMBER #IMPLIED 
409 points CDATA #IMPLIED 
410 > 
411 
412 
413 <!-- Different attributes related to objects: --> 
414 <!ELEMENT fillattr - O EMPTY> 
415 <!ATTLIST fillattr pattern %pats; #IMPLIED 
416 colour %cols; #IMPLIED> 
417 
418 <!-- Line attributes (type, thichness and colour). 
419 Thickness is measured in points --> 
420 <!ELEMENT lineattr - O EMPTY> 
421 <!ATTLIST lineattr type %lintyps; #IMPLIED 
422 thick NUMBER #IMPLIED 
423 colour %cols; #IMPLIED 
424 > 
425 
426 <!-- Text attributes. The different attributes declared to have 
427 type CDATA may assume values TRUE or FALSE. SGML doesn't allow more 
428 than one attribute in an ATTLIST to have same group. 
429 Hence: 
430 bold (TRUE | FALSE) 
431 is legal, but 
432 bold (TRUE | FALSE) 
433 italic (TRUE | FALSE) 
434 is not. --> 
435 <!ELEMENT textattr - O EMPTY> 
436 <!ATTLIST textattr font %fonts; #IMPLIED 
437 just %justs; #IMPLIED 
438 colour %cols; #IMPLIED 
439 bold CDATA #IMPLIED 
440 italic CDATA #IMPLIED 
441 underlin CDATA #IMPLIED 
442 outline CDATA #IMPLIED 
443 shadow CDATA #IMPLIED 
444 condense CDATA #IMPLIED 
445 extend CDATA #IMPLIED 
446 scbar CDATA #IMPLIED
447 size NUMBER #IMPLIED 
448 > 
449 
450 <!-- Object flags --> 
451 <!-- All flags attributes might assume values TRUE or FALSE. 
452 mask - object pickable or not. 
453 omit - object showable or not 
454 nobound - object boundary visible or not 
455 visible - visible or not --> 
456 
457 <!ELEMENT flags - O EMPTY> 
458 <!ATTLIST flags mask CDATA #IMPLIED 
459 omit CDATA #IMPLIED 
460 nobound CDATA #IMPLIED 
461 nosizing CDATA #IMPLIED 
462 visible CDATA #IMPLIED 
463 > 
464 
465 <!-- Place end of an arc. 
466 idref is a reference to the id of the place to connect to. 
467 endpoint is a reference to the object that the arc physically 
468 connects to. 
469 Since only one IDREF is recognised inside an ATTLIST, endpoint 
470 is declared to be CDATA. 
471 --> 
472 <!ELEMENT placeend - O EMPTY> 
473 <!ATTLIST placeend idref IDREF #IMPLIED 
474 endpoint CDATA #IMPLIED 
475 > 
476 
477 <!-- Transition end of an arc. Same reasoning as for the placeend --> 
478 <!ELEMENT transend - O EMPTY> 
479 <!ATTLIST transend idref IDREF #IMPLIED 
480 endpoint CDATA #IMPLIED 
481 > 
482 
483 <!-- First object connected by a connector --> 
484 <!ELEMENT node1 - O EMPTY> 
485 <!ATTLIST node1 idref IDREF #IMPLIED> 
486 
487 <!-- Second object connected by a connector --> 
488 <!ELEMENT node2 - O EMPTY> 
489 <!ATTLIST node2 idref IDREF #IMPLIED> 
490 
491 <!-- Attributes for a page --> 
492 <!-- name - name of page. 
493 number - the number of the page (this is NOT the id of the page) 
494 visbor - borders visible (TRUE/FALSE) 
495 --> 
496 <!ELEMENT pageattr - O EMPTY>
497 <!ATTLIST pageattr name CDATA #IMPLIED 
498 number NUMBER #IMPLIED 
499 visbor CDATA #IMPLIED 
500 > 
501 
502 <!-- Region attributes: --> 
503 <!-- colorap - Colour as parent 
504 sizewp - resize with parent 
505 hoffset - horisontal offset (in mm) 
506 voffset - vertical offset (in mm) 
507 --> 
508 
509 <!ELEMENT regattr - O EMPTY> 
510 <!ATTLIST regattr colorap CDATA #IMPLIED 
511 sizewp CDATA #IMPLIED 
512 hoffset CDATA #IMPLIED 
513 voffset CDATA #IMPLIED 
514 > 
515 
516 <!-- Connector attributes --> 
517 <!-- hdwidth - Arrow head width (in points) 
518 hdheight - Arrow head height (in points) 
519 txtwidth - Text width (in points) 
520 txtheight - Text height (in points) 
521 --> 
522 <!ELEMENT connattr - O EMPTY> 
523 <!ATTLIST connattr hdwidth NUMBER #IMPLIED 
524 hdheight NUMBER #IMPLIED 
525 txtwidth NUMBER #IMPLIED 
526 txtheight NUMBER #IMPLIED 
527 > 
528 
529 <!-- Window attributes --> 
530 <!-- open - open on load (TRUE/FALSE) 
531 width - Width (in pixels). 
532 height - Height (in pixels) --> 
533 <!ELEMENT winattr - O EMPTY> 
534 <!ATTLIST winattr open CDATA #IMPLIED 
535 width NUMBER #IMPLIED 
536 height NUMBER #IMPLIED 
537 xpos NUMBER #IMPLIED 
538 ypos NUMBER #IMPLIED 
539 > 
540 
541 <!-- Mode attributes --> 
542 <!-- Determines some simulation code options. --> 
543 <!ELEMENT modeattr - O EMPTY> 
544 <!ATTLIST modeattr siminc CDATA #IMPLIED 
545 observe CDATA #IMPLIED 
546 propocc CDATA #IMPLIED
547 interact CDATA #IMPLIED 
548 execcode CDATA #IMPLIED 
549 > 
550 
551 <!-- For substitution transitions --> 
552 <!-- subpage - The ID of the corresponding subpage 
553 portsock - List of port/socket assingments on the form: 
554 "(port1ID, socket1ID)(port2ID, socket2ID)...(portNID, 
555 socketID)" 
556 --> 
557 <!ELEMENT subst - O EMPTY> 
558 <!ATTLIST subst subpage IDREF #IMPLIED 
559 portsock CDATA #IMPLIED 
560 > 
561 
562 <!-- Port type --> 
563 <!ELEMENT port - O EMPTY> 
564 <!ATTLIST port type %prttyps; #IMPLIED> 
565 
566 <!-- Superpage end of substitution connectors --> 
567 <!ELEMENT sup-page - O EMPTY> 
568 <!ATTLIST sup-page idref IDREF #IMPLIED> 
569 
570 <!-- Subpage end of substitution connectors --> 
571 <!ELEMENT sub-page - O EMPTY> 
572 <!ATTLIST sub-page idref IDREF #IMPLIED> 
573 
574 <!-- Multiplicity of page --> 
575 <!-- insts - number of instances --> 
576 <!ELEMENT mult - O EMPTY> 
577 <!ATTLIST mult insts NUMBER #IMPLIED> 
578 
579 <!ELEMENT layering - O EMPTY> 
580 <!ATTLIST layering type %laytyps; #IMPLIED> 
581 ]>