| read | (x|<in-port> => <any>) | G | 
|  | returns sexpr result of parsing characters in a sequence. |  | 
| write | (x|<out-port> y|<any>) | G | 
|  | verbose printing.  prints strings with double quotes etc. |  | 
| writeln | (x|<out-port> y|<any>) | G | 
|  | ==  (seq (write x y) (newline x)) |  | 
| emit | (x|<out-port> y|<any>) | G | 
|  | concise printing (e.g., prints strings without double quotes). |  | 
| msg | (x|<out-port> message|<seq> args|...) | G | 
|  | formatted output using special commands embedded in message.
  supported commands are: which consume one argument at a time.  otherwise subsequent message
  characters are printed to port x 
  (cf. Dylan's and CL's format).%=   ->  (write x arg)
  %s   ->  (display x arg)
  %d   ->  (write x arg)
  %%  ->  (write-char x #\%)
  
 |  | 
| post | (message|<seq> args|...) | G | 
|  | ==  (app msg out message args) |  | 
|  |