improved doc, fixed errors

@@ -50,11 +50,14 @@ result without using `args`, option `char='*'` allows to use `*`
 instead of `@` (or any other character). For instance:
 instead of `@` (or any other character). For instance:
 
 
     tex("hello")                   => hello
     tex("hello")                   => hello
-    tex("\foo{@}", "$")  => \foo{\$}
+    tex(r"\foo{@}", "$")           => \foo{\$}
     tex("@@")                      => @
     tex("@@")                      => @
-    tex("@@@+@@@", "x")  => @@@x@@@
+    tex("@@@+@@@", "x", char="+")  => @@@x@@@
     
     
-Two more commands are available:
+So, string `s` is not escaped for LaTeX special characters, only the
+`args` are.
+
+Two more LaTeX commands are available:
 
 
  * `\pyc{pass}` inserts a pretty printed version of the Python snippet
  * `\pyc{pass}` inserts a pretty printed version of the Python snippet
    without evaluating it, environment `pycode` is similar but for a
    without evaluating it, environment `pycode` is similar but for a
@@ -84,5 +87,6 @@ Compile in three passes, like a bibTeX:
 Just run `latex -shell-escape jobname`. Pros: you use just one command
 Just run `latex -shell-escape jobname`. Pros: you use just one command
 and the results are inserted on the fly so everything is immediately
 and the results are inserted on the fly so everything is immediately
 consistent. Cons: it's slower (a server version of PyTeX is launched
 consistent. Cons: it's slower (a server version of PyTeX is launched
-and communication takes some time, this may be improved in the
-future).
+and communication between `latex` and the server takes some time, this
+may be improved in the future if this is caused by PyTeX, but I
+suspect it is `\write18` mechanism that is slow).