structs in order to distinguish them. For instance:
<pre>
struct s1 { int x; int y; }
struct s2 { double x; double t; }
struct s3 { int z; }
         becomes type s1 = { s1_x: int; s1_y: int }
                 and s2 = { s2_x: float; s2_t: float }
                 and s3 = { z: int }
</pre>
The labels for <span class=machine><span class=font-tt>s1</span></span> and <span class=machine><span class=font-tt>s2</span></span> have been prefixed by <span class=machine><span class=font-tt>s1</span></span><span cla