By picking and choosing the bits of the posted solutions that I like best, I
get the following:
letters=: (65}.a.)&(>:@i. {. [) NB. mine
diag=: (= {"1 ' '&,.)&.|. NB. Adapted from Dan's post
reflect=: |:@(, }.@|.)^:2 NB. Morten's use of power
reflect diag letters 'E'
A
B B
C C
D D
E E
D D
C C
B B
A
Or:
|:@(, }.@|.)^:2 (= {"1 ' '&,.)&.|. (65}.a.)&(>:@i. {. [) 'E'
|:@(, }.@|.)^:2 ({.&>~ # {. i:@#) (65}.a.)&(>:@i. {. [) 'E'
(, }.@|.)|:(|. , }.) (= {"1 ' ',.])'A'([ + i...@-.@-)&.(a.&i.) 'E'
The bit that took me the longest was to find a "nice" (short & simple) way of
getting the letters of the alphabet up to and including y.
I found Raul's & Dan's use of Under to get around the []IO=0 issue of the
discrepancy between the index and first y letters instructive.
Raul's use of Oblique (a verb I haven't seen used much before) was refreshing.
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