title: Correctly install a depenency from composer
body: <p>I have installed the last version of laravel (7).
  Now I need a certain package:( mercadopago/dx-php )</p>
  
  <p>And throws the following conflict:</p>
  
  <pre><code>Problem 1
      - Installation request for mercadopago/dx-php ^2.0 -&gt; satisfiable by mercadopago/dx-php[2.0.0].
      - Conclusion: remove doctrine/inflector 2.0.3
      - Conclusion: don't install doctrine/inflector 2.0.3
  
  - mercadopago/dx-php 2.0.0 requires doctrine/inflector ^1.0 -&gt; satisfiable by doctrine/inflector[1.0.x-dev, 1.1.x-dev, 1.2.x-dev, 1.3.1, 1.3.x-dev, 1.4.0, 1.4.1, 1.4.2, 1.4.3, 1.4.x-dev, v1.0, v1.0.1, v1.1.0, v1.2.0, v1.3.0].
  
   - Can only install one of: doctrine/inflector[1.4.0, 2.0.3].
      - Can only install one of: doctrine/inflector[1.4.1, 2.0.3].
      - Can only install one of: doctrine/inflector[1.4.2, 2.0.3].
      - Can only install one of: doctrine/inflector[1.4.3, 2.0.3].
      - Can only install one of: doctrine/inflector[1.4.x-dev, 2.0.3].
      - Can only install one of: doctrine/inflector[1.0.x-dev, 2.0.3].
      - Can only install one of: doctrine/inflector[1.1.x-dev, 2.0.3].
      - Can only install one of: doctrine/inflector[1.2.x-dev, 2.0.3].
      - Can only install one of: doctrine/inflector[1.3.1, 2.0.3].
      - Can only install one of: doctrine/inflector[1.3.x-dev, 2.0.3].
      - Can only install one of: doctrine/inflector[v1.0, 2.0.3].
      - Can only install one of: doctrine/inflector[v1.0.1, 2.0.3].
      - Can only install one of: doctrine/inflector[v1.1.0, 2.0.3].
      - Can only install one of: doctrine/inflector[v1.2.0, 2.0.3].
      - Can only install one of: doctrine/inflector[v1.3.0, 2.0.3].
      - Installation request for doctrine/inflector (locked at 2.0.3) -&gt; satisfiable by doctrine/inflector[2.0.3].
  </code></pre>
  
  <p>I tried: </p>
  
  <pre><code>composer depends doctrine/inflector
  </code></pre>
  
  <p>And throws: <code>laravel/framework  v7.15.0  requires  doctrine/inflector (^1.4|^2.0)</code> </p>
  
  <p>If I understood correctly, everything will work fine if I remove doctrine/inflector[2.0.3], and install, for example, doctrine/inflector[1.4.3].</p>
  
  <p>composer.lock has the following: </p>
  
  <pre><code>"name": "doctrine/inflector",
              "version": "2.0.3",
              "source": {... etc
  </code></pre>
  
  <p>What is the correct way of installing doctrine/inflector version 1.4.3, having already installed 2.0.3?</p>