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<?xml-stylesheet type="text/xsl" href="../../assets/xml/rss.xsl" media="all"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Calculemus (Publicaciones sobre Fundamentos)</title><link>https://jaalonso.github.io/calculemus/</link><description></description><atom:link href="https://jaalonso.github.io/calculemus/categories/cat_retos-en-lean-4/fundamentos.xml" rel="self" type="application/rss+xml"></atom:link><language>es</language><copyright>Contents © 2026 &lt;a href="mailto:"&gt;José A. Alonso&lt;/a&gt; 
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src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png"&gt;&lt;/a&gt;</copyright><lastBuildDate>Sun, 18 Oct 2026 17:46:51 GMT</lastBuildDate><generator>Nikola (getnikola.com)</generator><docs>http://blogs.law.harvard.edu/tech/rss</docs><item><title>Reto 7: La composición de funciones inyectivas es inyectiva</title><link>https://jaalonso.github.io/calculemus/posts/2026/06/21-composicion_de_funciones_inyectivas/</link><dc:creator>José A. Alonso</dc:creator><description>&lt;div&gt;&lt;p&gt;Demostrar que la composición de funciones inyectivas es inyectiva.&lt;/p&gt;
&lt;p&gt;Para ello, completar la siguiente teoría de Lean 4:&lt;/p&gt;
&lt;div class="code"&gt;&lt;pre class="code literal-block"&gt;&lt;span class="kn"&gt;import&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;Mathlib.Tactic&lt;/span&gt;

&lt;span class="kn"&gt;open&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;Function&lt;/span&gt;

&lt;span class="kd"&gt;variable&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;α&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kt"&gt;Type&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;_&lt;/span&gt;&lt;span class="o"&gt;}&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;β&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kt"&gt;Type&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;_&lt;/span&gt;&lt;span class="o"&gt;}&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;γ&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="kt"&gt;Type&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;_&lt;/span&gt;&lt;span class="o"&gt;}&lt;/span&gt;
&lt;span class="kd"&gt;variable&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;α&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="bp"&gt;→&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;β&lt;/span&gt;&lt;span class="o"&gt;}&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;{&lt;/span&gt;&lt;span class="n"&gt;g&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;β&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="bp"&gt;→&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;γ&lt;/span&gt;&lt;span class="o"&gt;}&lt;/span&gt;

&lt;span class="kd"&gt;example&lt;/span&gt;
&lt;span class="w"&gt;  &lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;hg&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;Injective&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;g&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;
&lt;span class="w"&gt;  &lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;hf&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;Injective&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt;
&lt;span class="w"&gt;  &lt;/span&gt;&lt;span class="n"&gt;Injective&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="n"&gt;g&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="bp"&gt;∘&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="n"&gt;f&lt;/span&gt;&lt;span class="o"&gt;)&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="o"&gt;:=&lt;/span&gt;
&lt;span class="kd"&gt;by&lt;/span&gt;&lt;span class="w"&gt; &lt;/span&gt;&lt;span class="gr"&gt;sorry&lt;/span&gt;
&lt;/pre&gt;&lt;/div&gt;

&lt;hr&gt;
&lt;p&gt;&lt;a href="https://jaalonso.github.io/calculemus/posts/2026/06/21-composicion_de_funciones_inyectivas/"&gt;Leer más…&lt;/a&gt; (quedan 3 minutos de lectura)&lt;/p&gt;&lt;/div&gt;</description><category>Funciones</category><category>Fundamentos</category><category>Inyectivas</category><category>Lean4</category><category>RetoLean4</category><guid>https://jaalonso.github.io/calculemus/posts/2026/06/21-composicion_de_funciones_inyectivas/</guid><pubDate>Sun, 21 Jun 2026 04:00:00 GMT</pubDate></item></channel></rss>