title: The source function in R
body: <p>Suppose we have a program <code> test.R </code> that calls two other programs <code> test1.R </code> and <code> test2.R </code>:</p>
  
  <pre><code>   source("test1.R")
     source("test2.R")
  </code></pre>
  
  <p>Does this mean that R runs <code> test1.R </code> first and then <code> test2.R </code>? </p>