Actually, both 2 b. and 11 b. are given identity elements when left
identities don't exist. Their identities are the right (direction)
identities.

Table of given, left, and right identities (2 indicates no identity):

   b=.3 :'y b./ $0'
   btab=.3 :'y b./~ 0 1'

   (, b :: 2:"0  ,  0 1 i."2 1~ [: (,: |:"2) btab"0) i. 16
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
2 1 0 2 0 0 0 0 2 1  2  1  2  1  2  2
2 1 2 2 0 0 0 0 2 1  2  2  2  1  2  2
2 1 0 0 2 2 0 0 2 1  2  1  2  2  2  2

For 16 through 31 b. , 0 and 1 should be changed to 0 and _1 .

Marshall

-----Original Message-----
From: Marshall Lochbaum [mailto:[email protected]] 
Sent: Wednesday, March 16, 2011 6:01 PM
To: 'Programming forum'
Subject: RE: [Jprogramming] Erroneous identity element for 17 b.

   b=.3 :'y b./ $0'
   b :: _:"0 i. 2 16
_ 1 0 _ 0 0 0 0 _  1 _ 1 _ 1 _ _
_ 1 0 _ 0 0 0 0 _ _1 _ 1 _ 1 _ _

It looks like the value for 25 b. is correct, but the values for 17 b. and
29 b. need to be corrected. I don't know about 27 b. .  11 b. has the
incorrect identity element:

   11 b./ $0
1
   1 (11 b.) 0 1
1 1

Marshall

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Henry Rich
Sent: Wednesday, March 16, 2011 3:34 PM
To: Programming forum
Subject: [Jprogramming] Erroneous identity element for 17 b.

    17 b./ $0
1


Should be _1 .  I haven't checked all the other b. codes.

    9!:14''
j701/beta/2010-11-24/22:45


Henry Rich
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