{"id":195,"date":"2006-02-09T14:28:40","date_gmt":"2006-02-09T18:28:40","guid":{"rendered":"http:\/\/blogs.law.harvard.edu\/yulelog\/2006\/02\/09\/a-well-formed-formula-wff-video\/"},"modified":"2006-02-09T14:28:40","modified_gmt":"2006-02-09T18:28:40","slug":"a-well-formed-formula-wff-video","status":"publish","type":"post","link":"https:\/\/archive.blogs.harvard.edu\/yulelog\/2006\/02\/09\/a-well-formed-formula-wff-video\/","title":{"rendered":"A “well-formed formula” (wff) video"},"content":{"rendered":"

<\/a><\/p>\n

David Weinberger<\/a> has expanded his resumé with an acting gig in a great little 3-minute movie called Get Human (the video)<\/a>. This is for everyone who has climbed the walls while groping up (or down) a phone tree. Great film — very wickedly funny, too. <\/p>\n

That part of the video with the phone tree options reminded me of a fiendish mathematical logics course the kids and I worked part of the way through a few years back. It was all about mastering the kind of convolutions offered by some especially non-human-userinterface-designed phone tree options: “if yes, press 1 and say no, if no press 2 and say yes,” except expressed in symbols. <\/p>\n

Modus ponens<\/i>, remember?:
\n1. If Statement A, then Statement B.
\n2. But Statement A.
\n3. Therefore, Statement B.<\/p>\n

Looks like this:
\n1. [P –> Q]
\n2. P
\n3. Therefore, Q. <\/p>\n

If you’re really stuck, use the contrapositive<\/a>, which allows you to reverse the direction of the conditional (that’s the “if A, then B” formulation):
\n[P –> Q] and [[~Q] –> [~P]] are equivalent formulas: If P then Q, and If not-Q, then not-P. It’s a double negative, but it’s logical. <\/p>\n

Well, logical as hell, maybe: the kind of logical used by automated systems, i.e., designed to drive us humans up a (phone) tree!<\/p>\n

Note:
\nDefinition of WFF (“well formed formula”) here<\/a>. Woof-woof!<\/p>\n","protected":false},"excerpt":{"rendered":"

David Weinberger has expanded his resumé with an acting gig in a great little 3-minute movie called Get Human (the video). This is for everyone who has climbed the walls while groping up (or down) a phone tree. Great film — very wickedly funny, too. That part of the video with the phone tree options […]<\/p>\n","protected":false},"author":311,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[600],"tags":[],"class_list":["post-195","post","type-post","status-publish","format-standard","hentry","category-yulelogstories"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/posts\/195","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/users\/311"}],"replies":[{"embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/comments?post=195"}],"version-history":[{"count":0,"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/posts\/195\/revisions"}],"wp:attachment":[{"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/media?parent=195"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/categories?post=195"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archive.blogs.harvard.edu\/yulelog\/wp-json\/wp\/v2\/tags?post=195"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}