{"id":7546,"date":"2022-11-30T06:00:01","date_gmt":"2022-11-30T04:00:01","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=7546"},"modified":"2023-04-15T12:03:26","modified_gmt":"2023-04-15T10:03:26","slug":"30-nov-22","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/30-nov-22\/","title":{"rendered":"El tipo de las f\u00f3rmulas proposicionales: Variables de una f\u00f3rmula"},"content":{"rendered":"<p>Usando el tipo de las f\u00f3rmulas proposicionales definido en el <a href=\"https:\/\/bit.ly\/3L3G2SX\">ejercicio anterior<\/a>, definir la funci\u00f3n<\/p>\n<pre lang=\"text\">\n   variables :: FProp -> [Char]\n<\/pre>\n<p>tal que <code>variables p<\/code> es la lista de las variables de la f\u00f3rmula <code>p<\/code>. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   \u03bb> variables (Impl (Var 'A') (Conj (Const False) (Neg (Var 'B'))))\n   \"AB\"\n   \u03bb> variables (Impl (Var 'A') (Conj (Var 'A') (Neg (Var 'B'))))\n   \"AAB\"\n<\/pre>\n<p><b>Soluciones<\/b><\/p>\n<p>A continuaci\u00f3n se muestran las <a href=\"#haskell\">soluciones en Haskell<\/a> y las <a href=\"#python\">soluciones en Python<\/a>.<\/p>\n<p><a name=\"haskell\"><\/a><br \/>\n<b>Soluciones en Haskell<\/b><\/p>\n<pre lang=\"haskell\">\nimport Tipo_de_formulas (FProp(..))\n\nvariables :: FProp -> [Char]\nvariables (Const _)  = []\nvariables (Var x)    = [x]\nvariables (Neg p)    = variables p\nvariables (Conj p q) = variables p ++ variables q\nvariables (Impl p q) = variables p ++ variables q\n<\/pre>\n<p><a name=\"python\"><\/a><br \/>\n<b>Soluciones en Python<\/b><\/p>\n<pre lang=\"python\">\nfrom src.tipo_de_formulas import Conj, Const, FProp, Impl, Neg, Var\n\ndef variables(f: FProp) -> list[str]:\n    match f:\n        case Const(_):\n            return []\n        case Var(x):\n            return [x]\n        case Neg(p):\n            return variables(p)\n        case Conj(p, q):\n            return variables(p) + variables(q)\n        case Impl(p, q):\n            return variables(p) + variables(q)\n    assert False\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Usando el tipo de las f\u00f3rmulas proposicionales definido en el ejercicio anterior, definir la funci\u00f3n variables :: FProp -> [Char] tal que variables p es la lista de las variables de la f\u00f3rmula p. Por ejemplo, \u03bb> variables (Impl (Var &#8216;A&#8217;) (Conj (Const False) (Neg (Var &#8216;B&#8217;)))) \u00abAB\u00bb \u03bb> variables (Impl (Var &#8216;A&#8217;) (Conj (Var&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"footnotes":"","_jetpack_memberships_contains_paid_content":false},"categories":[581],"tags":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7546"}],"collection":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/comments?post=7546"}],"version-history":[{"count":3,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7546\/revisions"}],"predecessor-version":[{"id":8055,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7546\/revisions\/8055"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=7546"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=7546"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=7546"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}