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.navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox biography vcard"><tbody><tr><th colspan="2" class="infobox-above" style="font-size:125%;"><div class="fn">Eric C. R. Hehner</div></th></tr><tr><th scope="row" class="infobox-label">Born</th><td class="infobox-data"><span style="display:none"> (<span class="bday">1947-09-16</span>) </span>September 16, 1947<span class="noprint ForceAgeToShow"> (age 77)</span><br /><div style="display:inline" class="birthplace"><a href="/wiki/Ottawa" title="Ottawa">Ottawa</a>, <a href="/wiki/Ontario" title="Ontario">Ontario</a>, <a href="/wiki/Canada" title="Canada">Canada</a></div></td></tr><tr><th scope="row" class="infobox-label">Education</th><td class="infobox-data"><a href="/wiki/Carleton_University" title="Carleton University">Carleton University</a> (<a href="/wiki/Bachelor_of_Science" title="Bachelor of Science">B.Sc.</a>, 1969)<br /><a href="/wiki/University_of_Toronto" title="University of Toronto">University of Toronto</a> (<a href="/wiki/Master_of_Science" title="Master of Science">M.Sc.</a>, 1970; <a href="/wiki/Doctor_of_Philosophy" title="Doctor of Philosophy">Ph.D.</a>, 1974)</td></tr><tr><th scope="row" class="infobox-label">Known for</th><td class="infobox-data"><a href="/wiki/Predicative_programming" title="Predicative programming">Predicative programming</a><br /><a href="/wiki/Formal_methods" title="Formal methods">Formal methods</a><br /><a href="/wiki/Quote_notation" class="mw-redirect" title="Quote notation">Quote notation</a><br /><a href="/wiki/ALGOL" title="ALGOL">ALGOL</a></td></tr><tr><td colspan="2" class="infobox-full-data"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1257001546"><b>Scientific career</b></td></tr><tr><th scope="row" class="infobox-label">Fields</th><td class="infobox-data category"><a href="/wiki/Computer_science" title="Computer science">Computer science</a><br /><a href="/wiki/Computer_programming" title="Computer programming">Programming</a></td></tr><tr><th scope="row" class="infobox-label">Institutions</th><td class="infobox-data"><a href="/wiki/University_of_Toronto" title="University of Toronto">University of Toronto</a></td></tr><tr style="display:none"><td colspan="2"> </td></tr><tr><th scope="row" class="infobox-label">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="http://www.cs.toronto.edu/~hehner">www<wbr />.cs<wbr />.toronto<wbr />.edu<wbr />/~hehner</a></span></td></tr></tbody></table> <p><b>Eric</b> "<b>Rick</b>" <b>C. R. Hehner</b> (born 16 September 1947) is a <a href="/wiki/Canadians" title="Canadians">Canadian</a> <a href="/wiki/Computer_scientist" title="Computer scientist">computer scientist</a>. He was born in <a href="/wiki/Ottawa" title="Ottawa">Ottawa</a>. He studied <a href="/wiki/Mathematics" title="Mathematics">mathematics</a> and <a href="/wiki/Physics" title="Physics">physics</a> at <a href="/wiki/Carleton_University" title="Carleton University">Carleton University</a>, graduating with a <a href="/wiki/Bachelor_of_Science" title="Bachelor of Science">Bachelor of Science</a> (B.Sc.) in 1969. He studied <a href="/wiki/Computer_science" title="Computer science">computer science</a> at the <a href="/wiki/University_of_Toronto" title="University of Toronto">University of Toronto</a>, graduating with a <a href="/wiki/Master_of_Science" title="Master of Science">Master of Science</a> (M.Sc.) in 1970, and a <a href="/wiki/Doctor_of_Philosophy" title="Doctor of Philosophy">Doctor of Philosophy</a> (Ph.D.) in 1974. He then joined the faculty there, becoming a full professor in 1983. He became the Bell University Chair in <a href="/wiki/Software_engineering" title="Software engineering">software engineering</a> in 2001, and retired in 2012.<sup id="cite_ref-Official_1-0" class="reference"><a href="#cite_note-Official-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p><p>Hehner's main research area is <a href="/wiki/Formal_methods" title="Formal methods">formal methods</a> of software design. His method, initially called <a href="/wiki/Predicative_programming" title="Predicative programming">predicative programming</a>, later called Practical Theory of Programming, is to consider each <a href="/wiki/Formal_specification" title="Formal specification">specification</a> to be a binary (<a href="/wiki/Boolean_domain" title="Boolean domain">boolean</a>) expression, and each programming construct to be a binary expression specifying the effect of executing the programming construct. <a href="/wiki/Refinement_(computing)" title="Refinement (computing)">Refinement</a> is just <a href="/wiki/Material_conditional" title="Material conditional">implication</a>. This is the simplest formal method, and the most general, applying to sequential, <a href="/wiki/Parallel_computing" title="Parallel computing">parallel</a>, stand-alone, communicating, terminating, nonterminating, natural-time, <a href="/wiki/Real-time_computing" title="Real-time computing">real-time</a>, <a href="/wiki/Deterministic_algorithm" title="Deterministic algorithm">deterministic</a>, and probabilistic programs, and includes time and space bounds. This idea has influenced other computer science researchers, including <a href="/wiki/Tony_Hoare" title="Tony Hoare">Tony Hoare</a>. </p><p>Hehner's other research areas include probabilistic programming, unified algebra, and high-level circuit design. In 1979, Hehner invented a generalization of <a href="/wiki/Method_of_complements" title="Method of complements">radix complement</a> called <a href="/wiki/Quote_notation" class="mw-redirect" title="Quote notation">quote notation</a>, which is a representation of the <a href="/wiki/Rational_number" title="Rational number">rational numbers</a> that allows easier arithmetic and precludes roundoff error. </p><p>He was involved with developing <a href="/wiki/International_standard" title="International standard">international standards</a> in programming and informatics, as a member of the <a href="/wiki/International_Federation_for_Information_Processing" title="International Federation for Information Processing">International Federation for Information Processing</a> (IFIP) <a href="/wiki/IFIP_Working_Group_2.1" title="IFIP Working Group 2.1">IFIP Working Group 2.1</a> on Algorithmic Languages and Calculi,<sup id="cite_ref-Official_1-1" class="reference"><a href="#cite_note-Official-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> which <a href="/wiki/Specification_(technical_standard)" title="Specification (technical standard)">specified</a>, maintains, and supports the <a href="/wiki/Programming_language" title="Programming language">programming languages</a> <a href="/wiki/ALGOL_60" title="ALGOL 60">ALGOL 60</a> and <a href="/wiki/ALGOL_68" title="ALGOL 68">ALGOL 68</a>.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> and of IFIP Working Group 2.3 on Programming Methodology.<sup id="cite_ref-Official_1-2" class="reference"><a href="#cite_note-Official-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Eric_Hehner&action=edit&section=1" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-Official-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-Official_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Official_1-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Official_1-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFHehner2020" class="citation web cs1">Hehner, Eric C. R. (3 May 2020). <a rel="nofollow" class="external text" href="http://www.cs.toronto.edu/~hehner/">"Eric C. R. Hehner"</a>. <i>Department of Computer Science</i>. <a href="/wiki/University_of_Toronto" title="University of Toronto">University of Toronto</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-07-27</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Department+of+Computer+Science&rft.atitle=Eric+C.+R.+Hehner&rft.date=2020-05-03&rft.aulast=Hehner&rft.aufirst=Eric+C.+R.&rft_id=http%3A%2F%2Fwww.cs.toronto.edu%2F~hehner%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJeuringMeertensGuttmann2016" class="citation web cs1">Jeuring, Johan; <a href="/wiki/Lambert_Meertens" title="Lambert Meertens">Meertens, Lambert</a>; Guttmann, Walter (2016-08-17). <a rel="nofollow" class="external text" href="https://ifipwg21wiki.cs.kuleuven.be/IFIP21/Profile">"Profile of IFIP Working Group 2.1"</a>. <i>Foswiki</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-10-16</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Foswiki&rft.atitle=Profile+of+IFIP+Working+Group+2.1&rft.date=2016-08-17&rft.aulast=Jeuring&rft.aufirst=Johan&rft.au=Meertens%2C+Lambert&rft.au=Guttmann%2C+Walter&rft_id=https%3A%2F%2Fifipwg21wiki.cs.kuleuven.be%2FIFIP21%2FProfile&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSwierstraGibbonsMeertens2011" class="citation web cs1">Swierstra, Doaitse; <a href="/wiki/Jeremy_Gibbons" title="Jeremy Gibbons">Gibbons, Jeremy</a>; <a href="/wiki/Lambert_Meertens" title="Lambert Meertens">Meertens, Lambert</a> (2011-03-02). <a rel="nofollow" class="external text" href="https://ifipwg21wiki.cs.kuleuven.be/IFIP21/ScopeEtc">"ScopeEtc: IFIP21: Foswiki"</a>. <i>Foswiki</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2020-10-16</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Foswiki&rft.atitle=ScopeEtc%3A+IFIP21%3A+Foswiki&rft.date=2011-03-02&rft.aulast=Swierstra&rft.aufirst=Doaitse&rft.au=Gibbons%2C+Jeremy&rft.au=Meertens%2C+Lambert&rft_id=https%3A%2F%2Fifipwg21wiki.cs.kuleuven.be%2FIFIP21%2FScopeEtc&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></span> </li> </ol></div></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHehner1984" class="citation journal cs1">Hehner, E. C. R. (1984). <a rel="nofollow" class="external text" href="https://doi.org/10.1145%2F69610.357988">"Predicative Programming"</a>. <i><a href="/wiki/Communications_of_the_ACM" title="Communications of the ACM">Communications of the ACM</a></i>. <b>27</b> (2): 134–151. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1145%2F69610.357988">10.1145/69610.357988</a></span>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:11577076">11577076</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Communications+of+the+ACM&rft.atitle=Predicative+Programming&rft.volume=27&rft.issue=2&rft.pages=134-151&rft.date=1984&rft_id=info%3Adoi%2F10.1145%2F69610.357988&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A11577076%23id-name%3DS2CID&rft.aulast=Hehner&rft.aufirst=E.+C.+R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1145%252F69610.357988&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHehner1990" class="citation journal cs1">Hehner, E. C. R. (1990). <a rel="nofollow" class="external text" href="https://doi.org/10.1016%2F0167-6423%2890%2990018-9">"A Practical Theory of Programming"</a>. <i>Science of Computer Programming</i>. <b>14</b> (2–3): 133–158. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1016%2F0167-6423%2890%2990018-9">10.1016/0167-6423(90)90018-9</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science+of+Computer+Programming&rft.atitle=A+Practical+Theory+of+Programming&rft.volume=14&rft.issue=2%E2%80%933&rft.pages=133-158&rft.date=1990&rft_id=info%3Adoi%2F10.1016%2F0167-6423%2890%2990018-9&rft.aulast=Hehner&rft.aufirst=E.+C.+R.&rft_id=https%3A%2F%2Fdoi.org%2F10.1016%252F0167-6423%252890%252990018-9&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHehner2004" class="citation journal cs1">Hehner, E. C. R. (2004). "From Boolean Algebra to Unified Algebra". <i><a href="/wiki/Mathematical_Intelligencer" class="mw-redirect" title="Mathematical Intelligencer">Mathematical Intelligencer</a></i>. <b>26</b> (2): 3–19. <a href="/wiki/CiteSeerX_(identifier)" class="mw-redirect" title="CiteSeerX (identifier)">CiteSeerX</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.638.1782">10.1.1.638.1782</a></span>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2FBF02985647">10.1007/BF02985647</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:61678587">61678587</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Mathematical+Intelligencer&rft.atitle=From+Boolean+Algebra+to+Unified+Algebra&rft.volume=26&rft.issue=2&rft.pages=3-19&rft.date=2004&rft_id=https%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fsummary%3Fdoi%3D10.1.1.638.1782%23id-name%3DCiteSeerX&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A61678587%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1007%2FBF02985647&rft.aulast=Hehner&rft.aufirst=E.+C.+R.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span></li> <li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHehnerHorspool" class="citation journal cs1">Hehner, E. C. R.; Horspool, R.N.S. <a rel="nofollow" class="external text" href="http://www.cs.toronto.edu/~hehner/ratno.pdf">"A new representation of the rational numbers for fast easy arithmetic"</a> <span class="cs1-format">(PDF)</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=A+new+representation+of+the+rational+numbers+for+fast+easy+arithmetic&rft.aulast=Hehner&rft.aufirst=E.+C.+R.&rft.au=Horspool%2C+R.N.S.&rft_id=http%3A%2F%2Fwww.cs.toronto.edu%2F~hehner%2Fratno.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AEric+Hehner" class="Z3988"></span> <span class="cs1-visible-error citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_journal" title="Template:Cite journal">cite journal</a>}}</code>: </span><span class="cs1-visible-error citation-comment">Cite journal requires <code class="cs1-code">|journal=</code> (<a href="/wiki/Help:CS1_errors#missing_periodical" title="Help:CS1 errors">help</a>)</span></li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Eric_Hehner&action=edit&section=2" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><span class="official-website"><span class="url"><a rel="nofollow" class="external text" href="http://www.cs.toronto.edu/~hehner/">Official website</a></span></span></li> <li><a rel="nofollow" class="external text" href="http://www.informatik.uni-trier.de/~ley/db/indices/a-tree/h/Hehner:Eric_C=_R=.html">DBLP publications</a></li> <li><a rel="nofollow" class="external text" href="http://www.cs.toronto.edu/~hehner/aPToP/">A Practical Theory of Programming</a>, Professor Hehner's book, available free in <a href="/wiki/PDF" title="PDF">PDF</a></li> <li><a rel="nofollow" class="external text" href="https://discoverarchives.library.utoronto.ca/index.php/eric-hehner-fonds">Eric Hehner archival papers</a> held at the <a rel="nofollow" class="external text" href="https://utarms.library.utoronto.ca/">University of Toronto Archives and Records Management Services</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul 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programming"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="ALGOL_programming" style="font-size:114%;margin:0 4em"><a href="/wiki/ALGOL" title="ALGOL">ALGOL</a> programming</div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Programming_language_implementation" title="Programming language implementation">Implementations</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Technical_standard" title="Technical standard">Technical<br />standards</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ALGOL_58" title="ALGOL 58">ALGOL 58</a></li> <li><a href="/wiki/ALGOL_60" title="ALGOL 60">ALGOL 60</a></li> <li><a href="/wiki/ALGOL_68" title="ALGOL 68">ALGOL 68</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Dialect_(computing)" class="mw-redirect" title="Dialect (computing)">Dialects</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ABC_ALGOL" title="ABC ALGOL">ABC ALGOL</a></li> <li><a href="/wiki/ALCOR" title="ALCOR">ALCOR</a></li> <li><a href="/wiki/ALGO" title="ALGO">ALGO</a></li> <li><a href="/wiki/ALGOL_68C" title="ALGOL 68C">ALGOL 68C</a></li> <li><a href="/wiki/ALGOL_68-R" title="ALGOL 68-R">ALGOL 68-R</a></li> <li><a href="/wiki/ALGOL_68RS" title="ALGOL 68RS">ALGOL 68RS</a> (<a href="/wiki/ELLA_(programming_language)" title="ELLA (programming language)">ELLA</a>)</li> <li><a href="/wiki/ALGOL_68S" title="ALGOL 68S">ALGOL 68S</a></li> <li><a href="/wiki/ALGOL_N" title="ALGOL N">ALGOL N</a></li> <li><a href="/wiki/ALGOL_W" title="ALGOL W">ALGOL W</a></li> <li><a href="/wiki/ALGOL_X" title="ALGOL X">ALGOL X</a></li> <li><a href="/wiki/Atlas_Autocode" title="Atlas Autocode">Atlas Autocode</a> (<a href="/wiki/Edinburgh_IMP" title="Edinburgh IMP">Edinburgh IMP</a>)</li> <li><a href="/wiki/Burroughs_Large_Systems#ALGOL" title="Burroughs Large Systems">Burroughs ALGOL</a></li> <li><a href="/wiki/CORAL" title="CORAL">CORAL</a> 66</li> <li><a href="/wiki/Dartmouth_ALGOL_30" title="Dartmouth ALGOL 30">Dartmouth ALGOL 30</a></li> <li><a href="/wiki/DASK" title="DASK">DASK</a> ALGOL</li> <li><a href="/wiki/DG/L" title="DG/L">DG/L</a></li> <li><a href="/wiki/Elliott_ALGOL" title="Elliott ALGOL">Elliott ALGOL</a></li> <li><a href="/wiki/Executive_Systems_Problem_Oriented_Language" title="Executive Systems Problem Oriented Language">Executive Systems Problem Oriented Language</a> (ESPOL) → New Executive Programming Language (<a href="/wiki/NEWP" title="NEWP">NEWP</a>)</li> <li><a href="/wiki/FLACC" title="FLACC">FLACC</a></li> <li><a href="/wiki/IMP_(programming_language)" title="IMP (programming language)">IMP</a></li> <li><a href="/wiki/JOVIAL" title="JOVIAL">JOVIAL</a></li> <li><a href="/wiki/English_Electric_KDF9" title="English Electric KDF9">Kidsgrove</a> Algol</li> <li><a href="/wiki/MAD_(programming_language)" title="MAD (programming language)">MAD</a></li> <li><a href="/wiki/Mary_(programming_language)" title="Mary (programming language)">Mary</a></li> <li><a href="/wiki/NELIAC" title="NELIAC">NELIAC</a></li> <li><a href="/wiki/RTL/2" title="RTL/2">RTL/2</a></li> <li><a href="/wiki/S-algol" title="S-algol">S-algol</a>, <a href="/wiki/PS-algol" title="PS-algol">PS-algol</a>, <a href="/wiki/Napier88" title="Napier88">Napier88</a></li> <li><a href="/wiki/Simula" title="Simula">Simula</a></li> <li>Small Machine ALGOL Like Language (<a href="/wiki/SMALL" title="SMALL">SMALL</a>)</li> <li><a href="/wiki/SMIL_(computer)" title="SMIL (computer)">SMIL</a> ALGOL</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Formalism_(philosophy_of_mathematics)" title="Formalism (philosophy of mathematics)">Formalisms</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Jensen%27s_device" title="Jensen's device">Jensen's device</a></li> <li><a href="/wiki/Van_Wijngaarden_grammar" title="Van Wijngaarden grammar">Van Wijngaarden grammar</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Community_of_practice" title="Community of practice">Community</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Organizations</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Professional_association" title="Professional association">Professional<br />associations</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/ALCOR" title="ALCOR">ALCOR</a> Group</li> <li><a href="/wiki/Association_for_Computing_Machinery" title="Association for Computing Machinery">Association for Computing Machinery</a> (ACM)</li> <li><a href="/wiki/BSI_Group" title="BSI Group">BSI Group</a></li> <li><a href="/wiki/GOST" title="GOST">Euro-Asian Council for Standardization, Metrology and Certification</a> (EASC)</li> <li><a href="/wiki/International_Federation_for_Information_Processing" title="International Federation for Information Processing">International Federation for Information Processing</a> (IFIP) <a href="/wiki/IFIP_Working_Group_2.1" title="IFIP Working Group 2.1">IFIP Working Group 2.1</a></li> <li><a href="/wiki/Gesellschaft_f%C3%BCr_Angewandte_Mathematik_und_Mechanik" title="Gesellschaft für Angewandte Mathematik und Mechanik">Society of Applied Mathematics and Mechanics</a> (GAMM)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Business</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Burroughs_Corporation" title="Burroughs Corporation">Burroughs Corporation</a></li> <li><a href="/wiki/Elliott_Brothers_(computer_company)" title="Elliott Brothers (computer company)">Elliott Brothers</a></li> <li><a href="/wiki/Regnecentralen" title="Regnecentralen">Regnecentralen</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Education</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Case_Western_Reserve_University" title="Case Western Reserve University">Case Institute of Technology</a></li> <li><a href="/wiki/University_of_Edinburgh" title="University of Edinburgh">University of Edinburgh</a></li> <li><a href="/wiki/University_of_St_Andrews" title="University of St Andrews">University of St Andrews</a></li> <li><a href="/wiki/Manchester_University" class="mw-redirect" title="Manchester University">Manchester University</a></li> <li><a href="/wiki/Massachusetts_Institute_of_Technology" title="Massachusetts Institute of Technology">Massachusetts Institute of Technology</a> (MIT)</li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Government</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Royal_Radar_Establishment" title="Royal Radar Establishment">Royal Radar Establishment</a> (RRE)</li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/ALGOL_58" title="ALGOL 58">ALGOL 58</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/John_Backus" title="John Backus">John Backus</a></li> <li><a href="/wiki/Friedrich_L._Bauer" title="Friedrich L. Bauer">Friedrich L. Bauer</a></li> <li><a href="/wiki/Hermann_Bottenbruch" title="Hermann Bottenbruch">Hermann Bottenbruch</a></li> <li><a href="/wiki/Charles_Katz" title="Charles Katz">Charles Katz</a></li> <li><a href="/wiki/Alan_Perlis" title="Alan Perlis">Alan Perlis</a></li> <li><a href="/wiki/Heinz_Rutishauser" title="Heinz Rutishauser">Heinz Rutishauser</a></li> <li><a href="/wiki/Klaus_Samelson" title="Klaus Samelson">Klaus Samelson</a></li> <li><a href="/wiki/Joseph_Henry_Wegstein" title="Joseph Henry Wegstein">Joseph Henry Wegstein</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/MAD_(programming_language)" title="MAD (programming language)">MAD</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Bruce_Arden" title="Bruce Arden">Bruce Arden</a></li> <li><a href="/wiki/Bernard_Galler" title="Bernard Galler">Bernard Galler</a></li> <li><a href="/wiki/Robert_M._Graham_(computer_scientist)" title="Robert M. Graham (computer scientist)">Robert M. Graham</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/ALGOL_60" title="ALGOL 60">ALGOL 60</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><td colspan="2" class="navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>Backus^</li> <li><a href="/wiki/Roland_Carl_Backhouse" title="Roland Carl Backhouse">Roland Carl Backhouse</a></li> <li>Bauer^</li> <li><a href="/wiki/Richard_Bird_(computer_scientist)" title="Richard Bird (computer scientist)">Richard Bird</a></li> <li><a href="/wiki/Stephen_R._Bourne" title="Stephen R. Bourne">Stephen R. Bourne</a></li> <li><a href="/wiki/Edsger_W._Dijkstra" title="Edsger W. Dijkstra">Edsger W. Dijkstra</a></li> <li><a href="/wiki/Andrey_Ershov" class="mw-redirect" title="Andrey Ershov">Andrey Ershov</a></li> <li><a href="/wiki/Robert_W._Floyd" title="Robert W. Floyd">Robert W. Floyd</a></li> <li><a href="/wiki/Jeremy_Gibbons" title="Jeremy Gibbons">Jeremy Gibbons</a></li> <li>Julien Green</li> <li><a href="/wiki/David_Gries" title="David Gries">David Gries</a></li> <li><a class="mw-selflink selflink">Eric Hehner</a></li> <li><a href="/wiki/Tony_Hoare" title="Tony Hoare">Tony Hoare</a></li> <li><a href="/wiki/J%C3%B8rn_Jensen" title="Jørn Jensen">Jørn Jensen</a></li> <li>Katz^</li> <li><a href="/wiki/Peter_Landin" title="Peter Landin">Peter Landin</a></li> <li><a href="/wiki/Tom_Maibaum" title="Tom Maibaum">Tom Maibaum</a></li> <li><a href="/wiki/Conor_McBride" title="Conor McBride">Conor McBride</a></li> <li><a href="/wiki/John_McCarthy_(computer_scientist)" title="John McCarthy (computer scientist)">John McCarthy</a></li> <li><a href="/wiki/Carroll_Morgan_(computer_scientist)" title="Carroll Morgan (computer scientist)">Carroll Morgan</a></li> <li><a href="/wiki/Peter_Naur" title="Peter Naur">Peter Naur</a></li> <li><a href="/wiki/Maurice_Nivat" title="Maurice Nivat">Maurice Nivat</a></li> <li><a href="/wiki/John_E._L._Peck" title="John E. L. Peck">John E. L. Peck</a></li> <li>Perlis^</li> <li><a href="/wiki/Brian_Randell" title="Brian Randell">Brian Randell</a></li> <li>Rutishauser^</li> <li>Samelson^</li> <li><a href="/wiki/Jacob_T._Schwartz" title="Jacob T. Schwartz">Jacob T. Schwartz</a></li> <li><a href="/wiki/Micha_Sharir" title="Micha Sharir">Micha Sharir</a></li> <li><a href="/wiki/David_Turner_(computer_scientist)" title="David Turner (computer scientist)">David Turner</a></li> <li><a href="/wiki/Bernard_Vauquois" title="Bernard Vauquois">Bernard Vauquois</a></li> <li><a href="/wiki/Eiiti_Wada" title="Eiiti Wada">Eiiti Wada</a></li> <li>Wegstein^</li> <li><a href="/wiki/Adriaan_van_Wijngaarden" title="Adriaan van Wijngaarden">Adriaan van Wijngaarden</a></li> <li><a href="/wiki/Mike_Woodger" title="Mike Woodger">Mike Woodger</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Simula" title="Simula">Simula</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ole-Johan_Dahl" title="Ole-Johan Dahl">Ole-Johan Dahl</a></li> <li><a href="/wiki/Kristen_Nygaard" title="Kristen Nygaard">Kristen Nygaard</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/ALGOL_68" title="ALGOL 68">ALGOL 68</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li>Bauer^</li> <li><a href="/wiki/Susan_G._Bond" title="Susan G. Bond">Susan G. Bond</a></li> <li>Bourne^</li> <li><a href="/wiki/Robert_Dewar" title="Robert Dewar">Robert Dewar</a></li> <li>Dijkstra^</li> <li><a href="https://de.wikipedia.org/wiki/Gerhard_Goos" class="extiw" title="de:Gerhard Goos">Gerhard Goos</a></li> <li><a href="/wiki/Michael_Guy" title="Michael Guy">Michael Guy</a></li> <li>Hoare^</li> <li><a href="/wiki/Cornelis_H._A._Koster" title="Cornelis H. A. Koster">Cornelis H. A. Koster</a></li> <li><a href="/wiki/Peter_Landin" title="Peter Landin">Peter Landin</a></li> <li><a href="/wiki/Charles_H._Lindsey" title="Charles H. Lindsey">Charles H. Lindsey</a></li> <li><a href="/wiki/Barry_J._Mailloux" title="Barry J. Mailloux">Barry J. Mailloux</a></li> <li>McCarthy^</li> <li><a href="/wiki/Lambert_Meertens" title="Lambert Meertens">Lambert Meertens</a></li> <li>Naur^</li> <li>Peck^</li> <li><a href="/wiki/Willem_van_der_Poel" title="Willem van der Poel">Willem van der Poel</a></li> <li>Randell^</li> <li><a href="/wiki/Douglas_T._Ross" title="Douglas T. Ross">Douglas T. Ross</a></li> <li>Samelson^</li> <li><a href="/wiki/Michel_Sintzoff" title="Michel Sintzoff">Michel Sintzoff</a></li> <li>van Wijngaarden^</li> <li><a href="/wiki/Niklaus_Wirth" title="Niklaus Wirth">Niklaus Wirth</a></li> <li>Woodger^</li> <li><a href="/wiki/Philip_Woodward" title="Philip Woodward">Philip Woodward</a></li> <li><a href="/wiki/Nobuo_Yoneda" title="Nobuo Yoneda">Nobuo Yoneda</a></li></ul> </div></td></tr></tbody></table><div> <ul><li><a href="/wiki/Hal_Abelson" title="Hal Abelson">Hal Abelson</a></li> <li><a href="/wiki/John_Barnes_(computer_scientist)" title="John Barnes (computer scientist)">John Barnes</a></li> <li><a href="/wiki/Tony_Brooker" title="Tony Brooker">Tony Brooker</a></li> <li><a href="/wiki/Ron_Morrison" title="Ron Morrison">Ron Morrison</a></li> <li><a href="/wiki/Peter_O%27Hearn" title="Peter O'Hearn">Peter O'Hearn</a></li> <li><a href="/wiki/John_C._Reynolds" title="John C. Reynolds">John C. Reynolds</a></li></ul></div></td></tr></tbody></table><div> <ul><li><a href="/wiki/ALGOL_Bulletin" title="ALGOL Bulletin">ALGOL Bulletin</a></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Comparison</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <li><a href="/wiki/ALGOL_58#ALGOL_58's_influence_on_ALGOL_60" title="ALGOL 58">ALGOL 58 influence on ALGOL 60</a></li> <li><a href="/wiki/ALGOL_68#Comparisons_with_other_languages" title="ALGOL 68">ALGOL 68 to other languages</a></li> <li><a href="/wiki/Comparison_of_ALGOL_68_and_C%2B%2B" title="Comparison of ALGOL 68 and C++">ALGOL 68 to C++</a></li> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><b>^ = full name and link in prior ALGOL version above</b><br /><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Algol_programming_language_family" title="Category:Algol programming language family">Category: ALGOL</a></b> <span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:ALGOL_60" title="Category:ALGOL 60">Category: ALGOL 60</a></b></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox authority-control" aria-labelledby="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q5386705#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Authority_control_databases_frameless&#124;text-top&#124;10px&#124;alt=Edit_this_at_Wikidata&#124;link=https&#58;//www.wikidata.org/wiki/Q5386705#identifiers&#124;class=noprint&#124;Edit_this_at_Wikidata" style="font-size:114%;margin:0 4em"><a href="/wiki/Help:Authority_control" title="Help:Authority control">Authority control databases</a> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q5386705#identifiers" title="Edit this at Wikidata"><img alt="Edit this at Wikidata" src="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/10px-OOjs_UI_icon_edit-ltr-progressive.svg.png" decoding="async" width="10" height="10" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/8a/OOjs_UI_icon_edit-ltr-progressive.svg/15px-OOjs_UI_icon_edit-ltr-progressive.svg.png 1.5x, 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class="uid"><a rel="nofollow" class="external text" href="https://id.loc.gov/authorities/n84172295">United States</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://catalogue.bnf.fr/ark:/12148/cb12411310q">France</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://data.bnf.fr/ark:/12148/cb12411310q">BnF data</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="http://olduli.nli.org.il/F/?func=find-b&local_base=NLX10&find_code=UID&request=987007343262005171">Israel</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Academics</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://ci.nii.ac.jp/author/DA00282263?l=en">CiNii</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.mathgenealogy.org/id.php?id=24014">Mathematics Genealogy Project</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://dl.acm.org/profile/81452616535">Association for Computing Machinery</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://dblp.org/pid/h/EricCRHehner">DBLP</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://mathscinet.ams.org/mathscinet/MRAuthorID/83440">MathSciNet</a></span></li></ul></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://www.deutsche-digitale-bibliothek.de/person/gnd/174101414">DDB</a></span></li></ul></div></td></tr></tbody></table></div> <p><br /> </p> <style data-mw-deduplicate="TemplateStyles:r1012311289">.mw-parser-output .asbox{position:relative;overflow:hidden}.mw-parser-output .asbox table{background:transparent}.mw-parser-output .asbox p{margin:0}.mw-parser-output .asbox p+p{margin-top:0.25em}.mw-parser-output .asbox-body{font-style:italic}.mw-parser-output .asbox-note{font-size:smaller}.mw-parser-output .asbox .navbar{position:absolute;top:-0.75em;right:1em;display:none}</style><div role="note" class="metadata plainlinks asbox stub"><table role="presentation"><tbody><tr class="noresize"><td><span style="vertical-align:middle;"><span class="mw-image-border" typeof="mw:File"><a href="/wiki/File:Flag_of_Canada_(Pantone).svg" class="mw-file-description"><img alt="Flag of Canada" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/30px-Flag_of_Canada_%28Pantone%29.svg.png" decoding="async" width="30" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/45px-Flag_of_Canada_%28Pantone%29.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/60px-Flag_of_Canada_%28Pantone%29.svg.png 2x" data-file-width="1200" data-file-height="600" /></a></span><span style="margin-left:-30px;"><span typeof="mw:File"><a href="/wiki/File:Crystal_Clear_app_Login_Manager_2.png" class="mw-file-description"><img alt="Biography icon" src="//upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/30px-Crystal_Clear_app_Login_Manager_2.png" decoding="async" width="30" height="30" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/45px-Crystal_Clear_app_Login_Manager_2.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/60px-Crystal_Clear_app_Login_Manager_2.png 2x" data-file-width="170" data-file-height="170" /></a></span></span></span></td><td><p class="asbox-body">This biography of a Canadian academic is a <a href="/wiki/Wikipedia:Stub" title="Wikipedia:Stub">stub</a>. You can help Wikipedia by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Eric_Hehner&action=edit">expanding it</a>.</p></td></tr></tbody></table><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Canada-academic-bio-stub" title="Template:Canada-academic-bio-stub"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Canada-academic-bio-stub" title="Template talk:Canada-academic-bio-stub"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Canada-academic-bio-stub" title="Special:EditPage/Template:Canada-academic-bio-stub"><abbr title="Edit this template">e</abbr></a></li></ul></div></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1012311289"><div role="note" class="metadata plainlinks asbox stub"><table role="presentation"><tbody><tr class="noresize"><td><big><b>P ≟ NP</b></big> </td><td><p class="asbox-body">This biographical article relating to a <a href="/wiki/Computer_scientist" title="Computer scientist">computer scientist</a> is a <a href="/wiki/Wikipedia:Stub" title="Wikipedia:Stub">stub</a>. You can help Wikipedia by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Eric_Hehner&action=edit">expanding it</a>.</p></td></tr></tbody></table><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Compu-scientist-stub" title="Template:Compu-scientist-stub"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Compu-scientist-stub" title="Template talk:Compu-scientist-stub"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Compu-scientist-stub" title="Special:EditPage/Template:Compu-scientist-stub"><abbr title="Edit this template">e</abbr></a></li></ul></div></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1012311289"><div role="note" class="metadata plainlinks asbox stub"><table role="presentation"><tbody><tr class="noresize"><td><span typeof="mw:File"><span><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Computer.svg/20px-Computer.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Computer.svg/30px-Computer.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Computer.svg/40px-Computer.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span> <span style="vertical-align:middle;"><span class="mw-image-border" typeof="mw:File"><a href="/wiki/File:Flag_of_Canada_(Pantone).svg" class="mw-file-description"><img alt="Flag of Canada" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/30px-Flag_of_Canada_%28Pantone%29.svg.png" decoding="async" width="30" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/45px-Flag_of_Canada_%28Pantone%29.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Canada_%28Pantone%29.svg/60px-Flag_of_Canada_%28Pantone%29.svg.png 2x" data-file-width="1200" data-file-height="600" /></a></span><span style="margin-left:-30px;"><span typeof="mw:File"><a href="/wiki/File:Crystal_Clear_app_Login_Manager_2.png" class="mw-file-description"><img alt="Biography icon" src="//upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/30px-Crystal_Clear_app_Login_Manager_2.png" decoding="async" width="30" height="30" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/45px-Crystal_Clear_app_Login_Manager_2.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/c/c2/Crystal_Clear_app_Login_Manager_2.png/60px-Crystal_Clear_app_Login_Manager_2.png 2x" data-file-width="170" data-file-height="170" /></a></span></span></span></td><td><p class="asbox-body">This biographical article relating to a Canadian computer specialist is a <a href="/wiki/Wikipedia:Stub" title="Wikipedia:Stub">stub</a>. You can help Wikipedia by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Eric_Hehner&action=edit">expanding it</a>.</p></td></tr></tbody></table><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Canada-compu-bio-stub" title="Template:Canada-compu-bio-stub"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Canada-compu-bio-stub" title="Template talk:Canada-compu-bio-stub"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Canada-compu-bio-stub" title="Special:EditPage/Template:Canada-compu-bio-stub"><abbr title="Edit this template">e</abbr></a></li></ul></div></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Eric_Hehner&oldid=1232630372">https://en.wikipedia.org/w/index.php?title=Eric_Hehner&oldid=1232630372</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:1947_births" title="Category:1947 births">1947 births</a></li><li><a href="/wiki/Category:Canadian_computer_scientists" title="Category:Canadian computer scientists">Canadian computer scientists</a></li><li><a href="/wiki/Category:Formal_methods_people" title="Category:Formal methods people">Formal methods people</a></li><li><a href="/wiki/Category:Living_people" title="Category:Living people">Living people</a></li><li><a href="/wiki/Category:Carleton_University_alumni" title="Category:Carleton University alumni">Carleton University alumni</a></li><li><a href="/wiki/Category:University_of_Toronto_alumni" title="Category:University of Toronto alumni">University of Toronto alumni</a></li><li><a href="/wiki/Category:Academic_staff_of_the_University_of_Toronto" title="Category:Academic staff of the University of Toronto">Academic staff of the University of Toronto</a></li><li><a href="/wiki/Category:Canadian_academic_biography_stubs" title="Category:Canadian academic biography stubs">Canadian academic biography stubs</a></li><li><a href="/wiki/Category:Computer_scientist_stubs" title="Category:Computer scientist stubs">Computer scientist stubs</a></li><li><a href="/wiki/Category:Canadian_computer_specialist_stubs" title="Category:Canadian computer specialist stubs">Canadian computer specialist stubs</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Articles_with_hCards" title="Category:Articles with hCards">Articles with hCards</a></li><li><a href="/wiki/Category:CS1_errors:_missing_periodical" title="Category:CS1 errors: missing periodical">CS1 errors: missing periodical</a></li><li><a href="/wiki/Category:Official_website_different_in_Wikidata_and_Wikipedia" title="Category:Official website different in Wikidata and Wikipedia">Official website different in Wikidata and Wikipedia</a></li><li><a href="/wiki/Category:All_stub_articles" title="Category:All stub articles">All stub articles</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 4 July 2024, at 19:12<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. 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