gistfile1.xml

<main>
  <function name="mean" package="base" vesion="2.13.1">
    <arg name="x" input="free" type="numeric" requisite="true" />
    <arg name="trim" input="free" type="numeric" default="0" />
    <arg name="na.rm" input="logical" default="FALSE" />
  </function>

  <function name="cor" package="stats" vesion="2.13.1">
    <arg name="x"      input="free" type="numeric; matrix; data.frame" requisite="true" />
    <arg name="y"      input="free" type="NULL; numeric; matrix; data.frame" default="NULL" />
    <arg name="use"    input="select">c("everything","all.obs","complete.obs","na.or.complete","pairwise.complete.obs")</arg>
    <arg name="method" input="select">c("pearson","kendall","spearman")</arg>
  </function>
</main>