>>  <<  Ndx  Usr  Pri  JfC  LJ  Phr  Dic  Rel  Voc  !:  wd  Help  Dictionary

Foreign !:

This conjunction is used to communicate with the host system as well as with the keyboard (as an input file) and with the screen (as an output file). It is also used to provide a variety of extra-lingual facilities, such as setting the form of function display, determining the class of a name (noun, verb, adverb, or conjunction), and listing all existing names in specified classes.

Appendix A shows all uses of the foreign conjunction.
 

   (mean=: +/ % #) a=: 2 3 5 7 11 13
6.83333

   mean
+/ % #

   9!:3 (4)
   mean
  +- / --- +                   Tree display of verb
--+- %
  +- # 

   9!:3 (2 4 5)
   mean
+-----+-+-+                    Boxed display
|+-+-+|%|#|
||+|/|| | |
|+-+-+| | |
+-----+-+-+
  +- / --- +                   Tree display
--+- % 
  +- #
+/ % #                         Linear display

   4!:0 'a';'mean'             Classes of names (noun 0, verb 3)
0 3

   4!:1 (3)                    List of names in class 3
+----+
|mean|
+----+

>>  <<  Ndx  Usr  Pri  JfC  LJ  Phr  Dic  Rel  Voc  !:  wd  Help  Dictionary