For details, see std.arg source code and ` arc --bind-doc "std/*" '
and examples in doc/Argile.txt .

1. Basic types
--------------
:nothing: :any: :anything: :type: :word:
:int: :nat: :real: :text: :syntax: :code:

2. Using other files
--------------------
:use           [{<word>|<text>}, ...] {<word>|<text>}
 (exporting    [<syntax>       , ...] <syntax>):
Example:

   use std, array, list, hash, regex
   use "foo/bar.arg" exporting :my type:
   Ctype "char" :my type: "[42]"

3. Basic variable definitions
-----------------------------

:let ((the) <type>) {<word>|<syntax>} ({=|be} <any>):
will define a global variable if used in global scope,
or a local one otherwise. Examples:

   let int x
   let the real PI be 3.1415926
   let :some string: = "some text here."
   let any_value

4. Basic function definitions
-----------------------------
: .<syntax>. (-> <type>) <code> :
will define a function (either global or local depending on scope),
and will also define local variables in body for each parameter.
Example:

   .: f <real x> :. -> real { -0.5 * ( (cos(2.0*M_PI*x/360.0)) - 1.0 ) }

