(?:`)?(?:gnu`free`documentation`license`version`1\.1,`march`2000)?(?:`)?copyright`\(c\)`2000`free`software`foundation,`inc\.`51`franklin`st,`fifth`floor,`boston,`ma`02110\-1301`usa`everyone`is`permitted`to`copy`and`distribute`verbatim`copies`of`this`license`document,`but`changing`it`is`not`allowed\.`(?:.{,20})`preamble`the`purpose`of`this`license`is`to`make`a`manual,`textbook,`or`other`written`document`free`in`the`sense`of`freedom:`to`assure`everyone`the`effective`freedom`to`copy`and`redistribute`it,`with`or`without`modifying`it,`either`commercially`or`noncommercially\.`secondarily,`this`license`preserves`for`the`author`and`publisher`a`way`to`get`credit`for`their`work,`while`not`being`considered`responsible`for`modifications`made`by`others\.`this`license`is`a`kind`of`copyleft`,`which`means`that`derivative`works`of`the`document`must`themselves`be`free`in`the`same`sense\.`it`complements`the`gnu`general`public`license,`which`is`a`copyleft`license`designed`for`free`software\.`we`have`designed`this`license`in`order`to`use`it`for`manuals`for`free`software,`because`free`software`needs`free`documentation:`a`free`program`should`come`with`manuals`providing`the`same`freedoms`that`the`software`does\.`but`this`license`is`not`limited`to`software`manuals;`it`can`be`used`for`any`textual`work,`regardless`of`subject`matter`or`whether`it`is`published`as`a`printed`book\.`we`recommend`this`license`principally`for`works`whose`purpose`is`instruction`or`reference\.`(?:.{,20})`applicability`and`definitions`this`license`applies`to`any`manual`or`other`work`that`contains`a`notice`placed`by`the`copyright`holder`saying`it`can`be`distributed`under`the`terms`of`this`license\.`the`document`,`below,`refers`to`any`such`manual`or`work\.`any`member`of`the`public`is`a`licensee,`and`is`addressed`as`you`\.`a`modified`version`of`the`document`means`any`work`containing`the`document`or`a`portion`of`it,`either`copied`verbatim,`or`with`modifications`and`or`translated`into`another`language\.`a`secondary`section`is`a`named`appendix`or`a`front\-`matter`section`of`the`document`that`deals`exclusively`with`the`relationship`of`the`publishers`or`authors`of`the`document`to`the`document`s`overall`subject`\(or`to`related`matters\)`and`contains`nothing`that`could`fall`directly`within`that`overall`subject\.`\(for`example,`if`the`document`is`in`part`a`textbook`of`mathematics,`a`secondary`section`may`not`explain`any`mathematics\.\)`the`relationship`could`be`a`matter`of`historical`connection`with`the`subject`or`with`related`matters,`or`of`legal,`commercial,`philosophical,`ethical`or`political`position`regarding`them\.`the`invariant`sections`are`certain`secondary`sections`whose`titles`are`designated,`as`being`those`of`invariant`sections,`in`the`notice`that`says`that`the`document`is`released`under`this`license\.`the`cover`texts`are`certain`short`passages`of`text`that`are`listed,`as`front\-`cover`texts`or`back\-`cover`texts,`in`the`notice`that`says`that`the`document`is`released`under`this`license\.`a`transparent`copy`of`the`document`means`a`machine\-`readable`copy,`represented`in`a`format`whose`specification`is`available`to`the`general`public,`whose`contents`can`be`viewed`and`edited`directly`and`straightforwardly`with`generic`text`editors`or`\(for`images`composed`of`pixels\)`generic`paint`programs`or`\(for`drawings\)`some`widely`available`drawing`editor,`and`that`is`suitable`for`input`to`text`formatters`or`for`automatic`translation`to`a`variety`of`formats`suitable`for`input`to`text`formatters\.`a`copy`made`in`an`otherwise`transparent`file`format`whose`markup`has`been`designed`to`thwart`or`discourage`subsequent`modification`by`readers`is`not`transparent\.`a`copy`that`is`not`transparent`is`called`opaque`\.`examples`of`suitable`formats`for`transparent`copies`include`plain`ascii`without`markup,`texinfo`input`format,`latex`input`format,`sgml`or`xml`using`a`publicly`available`dtd,`and`standard\-`conforming`simple`html`designed`for`human`modification\.`opaque`formats`include`postscript,`pdf,`proprietary`formats`that`can`be`read`and`edited`only`by`proprietary`word`processors,`sgml`or`xml`for`which`the`dtd`and`or`processing`tools`are`not`generally`available,`and`the`machine\-`generated`html`produced`by`some`word`processors`for`output`purposes`only\.`the`title`page`means,`for`a`printed`book,`the`title`page`itself,`plus`such`following`pages`as`are`needed`to`hold,`legibly,`the`material`this`license`requires`to`appear`in`the`title`page\.`for`works`in`formats`which`do`not`have`any`title`page`as`such,`title`page`means`the`text`near`the`most`prominent`appearance`of`the`work`s`title,`preceding`the`beginning`of`the`body`of`the`text\.`(?:.{,20})`verbatim`copying`you`may`copy`and`distribute`the`document`in`any`medium,`either`commercially`or`noncommercially,`provided`that`this`license,`the`copyright`notices,`and`the`license`notice`saying`this`license`applies`to`the`document`are`reproduced`in`all`copies,`and`that`you`add`no`other`conditions`whatsoever`to`those`of`this`license\.`you`may`not`use`technical`measures`to`obstruct`or`control`the`reading`or`further`copying`of`the`copies`you`make`or`distribute\.`however,`you`may`accept`compensation`in`exchange`for`copies\.`if`you`distribute`a`large`enough`number`of`copies`you`must`also`follow`the`conditions`in`section`3\.`you`may`also`lend`copies,`under`the`same`conditions`stated`above,`and`you`may`publicly`display`copies\.`(?:.{,20})`copying`in`quantity`if`you`publish`printed`copies`of`the`document`numbering`more`than`100,`and`the`document`s`license`notice`requires`cover`texts,`you`must`enclose`the`copies`in`covers`that`carry,`clearly`and`legibly,`all`these`cover`texts:`front\-`cover`texts`on`the`front`cover,`and`back\-`cover`texts`on`the`back`cover\.`both`covers`must`also`clearly`and`legibly`identify`you`as`the`publisher`of`these`copies\.`the`front`cover`must`present`the`full`title`with`all`words`of`the`title`equally`prominent`and`visible\.`you`may`add`other`material`on`the`covers`in`addition\.`copying`with`changes`limited`to`the`covers,`as`long`as`they`preserve`the`title`of`the`document`and`satisfy`these`conditions,`can`be`treated`as`verbatim`copying`in`other`respects\.`if`the`required`texts`for`either`cover`are`too`voluminous`to`fit`legibly,`you`should`put`the`first`ones`listed`\(as`many`as`fit`reasonably\)`on`the`actual`cover,`and`continue`the`rest`onto`adjacent`pages\.`if`you`publish`or`distribute`opaque`copies`of`the`document`numbering`more`than`100,`you`must`either`include`a`machine\-`readable`transparent`copy`along`with`each`opaque`copy,`or`state`in`or`with`each`opaque`copy`a`publicly\-`accessible`computer\-`network`location`containing`a`complete`transparent`copy`of`the`document,`free`of`added`material,`which`the`general`network\-`using`public`has`access`to`download`anonymously`at`no`charge`using`public\-`standard`network`protocols\.`if`you`use`the`latter`option,`you`must`take`reasonably`prudent`steps,`when`you`begin`distribution`of`opaque`copies`in`quantity,`to`ensure`that`this`transparent`copy`will`remain`thus`accessible`at`the`stated`location`until`at`least`one`year`after`the`last`time`you`distribute`an`opaque`copy`\(directly`or`through`your`agents`or`retailers\)`of`that`edition`to`the`public\.`it`is`requested,`but`not`required,`that`you`contact`the`authors`of`the`document`well`before`redistributing`any`large`number`of`copies,`to`give`them`a`chance`to`provide`you`with`an`updated`version`of`the`document\.`(?:.{,20})`modifications`you`may`copy`and`distribute`a`modified`version`of`the`document`under`the`conditions`of`sections`2`and`3`above,`provided`that`you`release`the`modified`version`under`precisely`this`license,`with`the`modified`version`filling`the`role`of`the`document,`thus`licensing`distribution`and`modification`of`the`modified`version`to`whoever`possesses`a`copy`of`it\.`in`addition,`you`must`do`these`things`in`the`modified`version:`(?:.{,20})`use`in`the`title`page`\(and`on`the`covers,`if`any\)`a`title`distinct`from`that`of`the`document,`and`from`those`of`previous`versions`\(which`should,`if`there`were`any,`be`listed`in`the`history`section`of`the`document\)\.`you`may`use`the`same`title`as`a`previous`version`if`the`original`publisher`of`that`version`gives`permission\.`(?:.{,20})`list`on`the`title`page,`as`authors,`one`or`more`persons`or`entities`responsible`for`authorship`of`the`modifications`in`the`modified`version,`together`with`at`least`five`of`the`principal`authors`of`the`document`\(all`of`its`principal`authors,`if`it`has`less`than`five\)\.`(?:.{,20})`state`on`the`title`page`the`name`of`the`publisher`of`the`modified`version,`as`the`publisher\.`(?:.{,20})`preserve`all`the`copyright`notices`of`the`document\.`(?:.{,20})`add`an`appropriate`copyright`notice`for`your`modifications`adjacent`to`the`other`copyright`notices\.`(?:.{,20})`include,`immediately`after`the`copyright`notices,`a`license`notice`giving`the`public`permission`to`use`the`modified`version`under`the`terms`of`this`license,`in`the`form`shown`in`the`addendum`below\.`(?:.{,20})`preserve`in`that`license`notice`the`full`lists`of`invariant`sections`and`required`cover`texts`given`in`the`document`s`license`notice\.`(?:.{,20})`include`an`unaltered`copy`of`this`license\.`(?:.{,20})`preserve`the`section`entitled`history`,`and`its`title,`and`add`to`it`an`item`stating`at`least`the`title,`year,`new`authors,`and`publisher`of`the`modified`version`as`given`on`the`title`page\.`if`there`is`no`section`entitled`history`in`the`document,`create`one`stating`the`title,`year,`authors,`and`publisher`of`the`document`as`given`on`its`title`page,`then`add`an`item`describing`the`modified`version`as`stated`in`the`previous`sentence\.`(?:.{,20})`preserve`the`network`location,`if`any,`given`in`the`document`for`public`access`to`a`transparent`copy`of`the`document,`and`likewise`the`network`locations`given`in`the`document`for`previous`versions`it`was`based`on\.`these`may`be`placed`in`the`history`section\.`you`may`omit`a`network`location`for`a`work`that`was`published`at`least`four`years`before`the`document`itself,`or`if`the`original`publisher`of`the`version`it`refers`to`gives`permission\.`(?:.{,20})`in`any`section`entitled`acknowledgements`or`dedications`,`preserve`the`section`s`title,`and`preserve`in`the`section`all`the`substance`and`tone`of`each`of`the`contributor`acknowledgements`and`or`dedications`given`therein\.`(?:.{,20})`preserve`all`the`invariant`sections`of`the`document,`unaltered`in`their`text`and`in`their`titles\.`section`numbers`or`the`equivalent`are`not`considered`part`of`the`section`titles\.`(?:.{,20})`delete`any`section`entitled`endorsements`\.`such`a`section`may`not`be`included`in`the`modified`version\.`(?:.{,20})`do`not`retitle`any`existing`section`as`endorsements`or`to`conflict`in`title`with`any`invariant`section\.`if`the`modified`version`includes`new`front\-`matter`sections`or`appendices`that`qualify`as`secondary`sections`and`contain`no`material`copied`from`the`document,`you`may`at`your`option`designate`some`or`all`of`these`sections`as`invariant\.`to`do`this,`add`their`titles`to`the`list`of`invariant`sections`in`the`modified`version`s`license`notice\.`these`titles`must`be`distinct`from`any`other`section`titles\.`you`may`add`a`section`entitled`endorsements`,`provided`it`contains`nothing`but`endorsements`of`your`modified`version`by`various`parties\-`for`example,`statements`of`peer`review`or`that`the`text`has`been`approved`by`an`organization`as`the`authoritative`definition`of`a`standard\.`you`may`add`a`passage`of`up`to`five`words`as`a`front\-`cover`text,`and`a`passage`of`up`to`25`words`as`a`back\-`cover`text,`to`the`end`of`the`list`of`cover`texts`in`the`modified`version\.`only`one`passage`of`front\-`cover`text`and`one`of`back\-`cover`text`may`be`added`by`\(or`through`arrangements`made`by\)`any`one`entity\.`if`the`document`already`includes`a`cover`text`for`the`same`cover,`previously`added`by`you`or`by`arrangement`made`by`the`same`entity`you`are`acting`on`behalf`of,`you`may`not`add`another;`but`you`may`replace`the`old`one,`on`explicit`permission`from`the`previous`publisher`that`added`the`old`one\.`the`author\(s\)`and`publisher\(s\)`of`the`document`do`not`by`this`license`give`permission`to`use`their`names`for`publicity`for`or`to`assert`or`imply`endorsement`of`any`modified`version\.`(?:.{,20})`combining`documents`you`may`combine`the`document`with`other`documents`released`under`this`license,`under`the`terms`defined`in`section`4`above`for`modified`versions,`provided`that`you`include`in`the`combination`all`of`the`invariant`sections`of`all`of`the`original`documents,`unmodified,`and`list`them`all`as`invariant`sections`of`your`combined`work`in`its`license`notice\.`the`combined`work`need`only`contain`one`copy`of`this`license,`and`multiple`identical`invariant`sections`may`be`replaced`with`a`single`copy\.`if`there`are`multiple`invariant`sections`with`the`same`name`but`different`contents,`make`the`title`of`each`such`section`unique`by`adding`at`the`end`of`it,`in`parentheses,`the`name`of`the`original`author`or`publisher`of`that`section`if`known,`or`else`a`unique`number\.`make`the`same`adjustment`to`the`section`titles`in`the`list`of`invariant`sections`in`the`license`notice`of`the`combined`work\.`in`the`combination,`you`must`combine`any`sections`entitled`history`in`the`various`original`documents,`forming`one`section`entitled`history`;`likewise`combine`any`sections`entitled`acknowledgements`,`and`any`sections`entitled`dedications`\.`you`must`delete`all`sections`entitled`endorsements\.`(?:.{,20})`collections`of`documents`you`may`make`a`collection`consisting`of`the`document`and`other`documents`released`under`this`license,`and`replace`the`individual`copies`of`this`license`in`the`various`documents`with`a`single`copy`that`is`included`in`the`collection,`provided`that`you`follow`the`rules`of`this`license`for`verbatim`copying`of`each`of`the`documents`in`all`other`respects\.`you`may`extract`a`single`document`from`such`a`collection,`and`distribute`it`individually`under`this`license,`provided`you`insert`a`copy`of`this`license`into`the`extracted`document,`and`follow`this`license`in`all`other`respects`regarding`verbatim`copying`of`that`document\.`(?:.{,20})`aggregation`with`independent`works`a`compilation`of`the`document`or`its`derivatives`with`other`separate`and`independent`documents`or`works,`in`or`on`a`volume`of`a`storage`or`distribution`medium,`does`not`as`a`whole`count`as`a`modified`version`of`the`document,`provided`no`compilation`copyright`is`claimed`for`the`compilation\.`such`a`compilation`is`called`an`aggregate`,`and`this`license`does`not`apply`to`the`other`self\-`contained`works`thus`compiled`with`the`document,`on`account`of`their`being`thus`compiled,`if`they`are`not`themselves`derivative`works`of`the`document\.`if`the`cover`text`requirement`of`section`3`is`applicable`to`these`copies`of`the`document,`then`if`the`document`is`less`than`one`quarter`of`the`entire`aggregate,`the`document`s`cover`texts`may`be`placed`on`covers`that`surround`only`the`document`within`the`aggregate\.`otherwise`they`must`appear`on`covers`around`the`whole`aggregate\.`(?:.{,20})`translation`translation`is`considered`a`kind`of`modification,`so`you`may`distribute`translations`of`the`document`under`the`terms`of`section`4\.`replacing`invariant`sections`with`translations`requires`special`permission`from`their`copyright`holders,`but`you`may`include`translations`of`some`or`all`invariant`sections`in`addition`to`the`original`versions`of`these`invariant`sections\.`you`may`include`a`translation`of`this`license`provided`that`you`also`include`the`original`english`version`of`this`license\.`in`case`of`a`disagreement`between`the`translation`and`the`original`english`version`of`this`license,`the`original`english`version`will`prevail\.`(?:.{,20})`termination`you`may`not`copy,`modify,`sublicense,`or`distribute`the`document`except`as`expressly`provided`for`under`this`license\.`any`other`attempt`to`copy,`modify,`sublicense`or`distribute`the`document`is`void,`and`will`automatically`terminate`your`rights`under`this`license\.`however,`parties`who`have`received`copies,`or`rights,`from`you`under`this`license`will`not`have`their`licenses`terminated`so`long`as`such`parties`remain`in`full`compliance\.`(?:.{,20})`future`revisions`of`this`license`the`free`software`foundation`may`publish`new,`revised`versions`of`the`gnu`free`documentation`license`from`time`to`time\.`such`new`versions`will`be`similar`in`spirit`to`the`present`version,`but`may`differ`in`detail`to`address`new`problems`or`concerns\.`see`http:`www\.`gnu\.`org`copyleft`\.`each`version`of`the`license`is`given`a`distinguishing`version`number\.`if`the`document`specifies`that`a`particular`numbered`version`of`this`license`or`any`later`version`applies`to`it,`you`have`the`option`of`following`the`terms`and`conditions`either`of`that`specified`version`or`of`any`later`version`that`has`been`published`\(not`as`a`draft\)`by`the`free`software`foundation\.`if`the`document`does`not`specify`a`version`number`of`this`license,`you`may`choose`any`version`ever`published`\(not`as`a`draft\)`by`the`free`software`foundation\.(?:`)?(?:addendum:`how`to`use`this`license`for`your`documents`to`use`this`license`in`a`document`you`have`written,`include`a`copy`of`the`license`in`the`document`and`put`the`following`copyright`and`license`notices`just`after`the`title`page:`copyright`\(c\)`year`your`name\.`permission`is`granted`to`copy,`distribute`and`or`modify`this`document`under`the`terms`of`the`gnu`free`documentation`license,`version`1\.1`or`any`later`version`published`by`the`free`software`foundation;`with`(?:(?:the\`Invariant\`Sections\`\`\`\`\`\`\`\`\`being\`.+|no\`Invariant\`Sections)),`with`(?:(?:the\`Front\-Cover\`Texts\`being\`.+|no\`Front\-Cover\`Texts)),`and`with`(?:(?:the\`Back\-Cover\`Texts\`being\`.+|no\`Back\-Cover\`Texts))\.`a`copy`of`the`license`is`included`in`the`section`entitled`gnu`free`documentation`license`\.`if`you`have`no`invariant`sections,`write`with`no`invariant`sections`instead`of`saying`which`ones`are`invariant\.`if`you`have`no`front\-`cover`texts,`write`no`front\-`cover`texts`instead`of`front\-`cover`texts`being`list`;`likewise`for`back\-`cover`texts\.`if`your`document`contains`nontrivial`examples`of`program`code,`we`recommend`releasing`these`examples`in`parallel`under`your`choice`of`free`software`license,`such`as`the`gnu`general`public`license,`to`permit`their`use`in`free`software\.)?(?:`)?