NB. ,y ------------------------------------------------------------------

t        -: ,(i. 2 3 4){t=.?24$2
(|.t)    -: ,(i.-2 3 4){t=.?24$2

(i.24)   -: ,i. 2 3 4
(|.i.24) -: ,i.-2 3 4

t        -: ,(i. 2 3 4){t=.o._50+?24$1232
(|.t)    -: ,(i.-2 3 4){t=.o._50+?24$2123

t        -: ,(i. 2 3 4){t=.j./_50+?2 24$1232
(|.t)    -: ,(i.-2 3 4){t=.j./_50+?2 24$2123

t        -: ,(i. 2 3 4){t=.24$3 4;;:'j./_50+?2 24$123 2'
(|.t)    -: ,(i.-2 3 4){t=.24$5j6;;:'j./_50+?2 24$2 123'

0 = #,0 3 2 3$0 1
0 = #,0 3 4 5$a.
0 = #,i.2 3 4 0
0 = #,o.i.2 3 4 0
0 = #,0j1*i.2 3 0 4
0 = #, 2 0 2 $<0

1 = #,0
1 = #,'a'
1 = #,9
1 = #,3.4
1 = #,3j4
1 = #,<123


NB. ,"r y ---------------------------------------------------------------

([ -: ,"1) ?4 13$1e8
(, -: ,"2) ?4 13$1e8
(,"0 x) -: (($x),1)$,x=.o.?4 13$1e8
(,"_1 -: ,"2) (?4 7 11$#x){x=.'amelioration delicatessen'
(,"2 x) -: 4 77$,x=.?4 7 11$2

(i.0 24 ) -: ,"3 i.0 2 3 4
(i.2 3 0) -: ,"_2 i.2 3 5 7 11 0

'limit error' -: ,"2 etx (>IF64{0 2e9 2;0 5e18 2)$9


NB. x,y -----------------------------------------------------------------

NB. atom-atom
0 1    -: 0,1
'ab'   -: 'a','b'
3 4    -: 3,4
1 _4.5 -: 1,_4.5
3 4j5  -: 3,4j5

NB. atom-list
0 1 1 0 0   -: 0, 1 1 0 0
1 1 0 0 0   -: 0,~1 1 0 0
'abcde'     -: 'abcd', 'e'
'eabcd'     -: 'abcd',~'e'
3 4 7 5 6   -: 3, 4 7 5 6
4 7 5 6 3   -: 3,~4 7 5 6
3 4 7.5 6 8 -: 3, 4 7.5 6 8
4 7.5 6 8 3 -: 3,~4 7.5 6 8
3 4 7j5 6 8 -: 3 4 7j5, 6 8
6 8 3 4 7j5 -: 3 4 7j5,~6 8

NB. atom-array
(5 2$9 9,i.8)   -: 9, i.4 2
(5 2$(i.8),9 9) -: 9,~i.4 2

NB. atom-empty
(,' ') -: ' ',''
5 0    -: $ ' ',4 0  $'a'
5 0 3  -: $ ' ',4 0 3$'a'

NB. list-list
0 1 1 0 0   -: 0 1 1,0 0
'abcde'     -: 'ab','cde'
3 4 7 5 6   -: 3 4,7 5 6
3 4 7.5 6 8 -: 3 4 7.5,6 8
3 4 7j5 6 8 -: 3 4,7j5 6 8

NB. list-array
(9 10 11, 4 3{.i.4 2) -: 9 10 11, i.4 2
(9 10 11,~4 3{.i.4 2) -: 9 10 11,~i.4 2
(5 2$0 0, i.8)        -: ''  , i.4 2
(5 2$(i.8),0 0)       -: ($0),~i.4 2

NB. numeric
x=.i.2 6
t=.i.4 3 2
5 3 6 -: $x,t
5 3 6 -: $t,x
(((}.$t)$1), t) -: 1, t
(((}.$t)$1),~t) -: 1,~t
((1 3 2{.,:,:99 13), t) -: 99 13, t
((1 3 2{.,:,:99 13),~t) -: 99 13,~t
(1 0 0+$t) -: $(|.2{t), t
(1 0 0+$t) -: $(|.2{t),~t
(2 1 1*$t) -: $(|.t), t
(2 1 1*$t) -: $(|.t),~t

(3 6$(6$0), ,x) -: ($0), x
(3 6$(6$0),~,x) -: ($0),~x
(3 6$(6$0), ,x) -: '', x
(3 6$(6$0),~,x) -: '',~x
(3 6$(6$0), ,x) -: (0$<''), x
(3 6$(6$0),~,x) -: (0$<''),~x

NB. literal
x=.a.{~97+i.2 6
t=.a.{~97+i.4 3 2
5 3 6 -: $x,t
5 3 6 -: $t,x
(((}.$t)$'a'), t) -: 'a', t
(((}.$t)$'a'),~t) -: 'a',~t
((1 3 2{.,:,:'*&'), t) -: '*&', t
((1 3 2{.,:,:'*&'),~t) -: '*&',~t
(1 0 0+$t) -: $(|.2{t), t
(1 0 0+$t) -: $(|.2{t),~t
(2 1 1*$t) -: $(|.t), t
(2 1 1*$t) -: $(|.t),~t

(3 6$(6$' '), ,x) -: ($0), x
(3 6$(6$' '),~,x) -: ($0),~x
(3 6$(6$' '), ,x) -: '', x
(3 6$(6$' '),~,x) -: '',~x
(3 6$(6$' '), ,x) -: (0$<''), x
(3 6$(6$' '),~,x) -: (0$<''),~x

NB. boxed
x=.2 6$;:'(2 1 1*$t) -: $(|.t),~t'
t=.4 3 2$;:'((a.{~66+i.3 2),~(1,$t)$,t) -: (a.{~66+i.3 2),~t'
5 3 6 -: $x,t
5 3 6 -: $t,x
(((}.$t)$<i.8), t) -: (<i.8), t
(((}.$t)$<i.8),~t) -: (<i.8),~t
((1 3 2{.,:,:9;10 11), t) -: (9;10 11), t
((1 3 2{.,:,:9;10 11),~t) -: (9;10 11),~t
(1 0 0+$t) -: $(|.2{t), t
(1 0 0+$t) -: $(|.2{t),~t
(2 1 1*$t) -: $(|.t), t
(2 1 1*$t) -: $(|.t),~t

(3 6$(6$<''), ,x) -: ($0), x
(3 6$(6$<''),~,x) -: ($0),~x
(3 6$(6$<''), ,x) -: '', x
(3 6$(6$<''),~,x) -: '',~x
(3 6$(6$<''), ,x) -: (0$<''), x
(3 6$(6$<''),~,x) -: (0$<''),~x

x=.?31 2$1e5 [ y=.?1 1$1e5
x -: }:x,y
x -: }.y,x

x=.a.{~?31 2$#a. [ y=.a.{~?1 1$#a.
x -: }:x,y
x -: }.y,x

'domain error' -: 3 4 , etx 'abc'
'domain error' -: 3 4 ,~etx 'abc'
'domain error' -: 'ab', etx 'a';3
'domain error' -: 'ab',~etx 'a';3
'domain error' -: 3 4 , etx 'a';3
'domain error' -: 3 4 ,~etx 'a';3


NB. x,y empty and fills -------------------------------------------------

(3 5 2 4{.' ') -: (3 2 0$''), 2 5 0 4$''
(3 5 2 4{.' ') -: (3 2 0$''),~2 5 0 4$''
(3 5 2 0{.' ') -: (3 2 0$''), 2 5 0 0$''
(3 5 2 0{.' ') -: (3 2 0$''),~2 5 0 0$''

(3 5 2 4{.a:) -: (3 2 0$a:), 2 5 0 4$a:
(3 5 2 4{.a:) -: (3 2 0$a:),~2 5 0 4$a:
(3 5 2 0{.a:) -: (3 2 0$a:), 2 5 0 0$a:
(3 5 2 0{.a:) -: (3 2 0$a:),~2 5 0 0$a:

(3 5 2 4{.0) -: (3 2 0$0), 2 5 0 4$0
(3 5 2 4{.0) -: (3 2 0$0),~2 5 0 4$0
(3 5 2 0{.0) -: (3 2 0$0), 2 5 0 0$0
(3 5 2 0{.0) -: (3 2 0$0),~2 5 0 0$0

(3 5 2 4{.0) -: (3 2 0$0), 2 5 0 4$3.4
(3 5 2 4{.0) -: (3 2 0$0), 2 5 0 4$3j4
(3 5 2 4{.0) -: (3 2 0$0), 2 5 0 4$3x
(3 5 2 4{.0) -: (3 2 0$0), 2 5 0 4$3r4

(x,~  4$99 99, 4$  0) -: 99 99 ,      x=.i.2 4
(x,~  4$99 99, 4$  1) -: 99 99 ,!.1   x=.i.2 4
(x,~  4$99 99, 4$100) -: 99 99 ,!.100 x=.i.2 4
(x,~  4$99 99, 4$3.5) -: 99 99 ,!.3.5 x=.i.2 4
(x,~  4$99 99, 4$3j5) -: 99 99 ,!.3j5 x=.i.2 4

(x,~3 4$99 99,12$  0) -: 99 99 ,      x=.i.2 3 4
(x,~3 4$99 99,12$  1) -: 99 99 ,!.1   x=.i.2 3 4
(x,~3 4$99 99,12$100) -: 99 99 ,!.100 x=.i.2 3 4
(x,~3 4$99 99,12$3.5) -: 99 99 ,!.3.5 x=.i.2 3 4
(x,~3 4$99 99,12$3j5) -: 99 99 ,!.3j5 x=.i.2 3 4

(x,   4$99 99, 4$  0) -: 99 99 ,     ~x=.i.2 4
(x,   4$99 99, 4$  1) -: 99 99 ,!.1  ~x=.i.2 4
(x,   4$99 99, 4$100) -: 99 99 ,!.100~x=.i.2 4
(x,   4$99 99, 4$3.5) -: 99 99 ,!.3.5~x=.i.2 4
(x,   4$99 99, 4$3j5) -: 99 99 ,!.3j5~x=.i.2 4

(x, 3 4$99 99,12$  0) -: 99 99 ,     ~x=.i.2 3 4
(x, 3 4$99 99,12$  1) -: 99 99 ,!.1  ~x=.i.2 3 4
(x, 3 4$99 99,12$100) -: 99 99 ,!.100~x=.i.2 3 4
(x, 3 4$99 99,12$3.5) -: 99 99 ,!.3.5~x=.i.2 3 4
(x, 3 4$99 99,12$3j5) -: 99 99 ,!.3j5~x=.i.2 3 4

(x,~  4$'ab',  4$' ') -: 'ab'  ,      x=.2 4$'short shrift'
(x,~  4$'ab',  4$'q') -: 'ab'  ,!.'q' x
(x,~3 4$'ab', 12$' ') -: 'ab'  ,      x=.2 3 4$'hey nonny nonny'
(x,~3 4$'ab', 12$'q') -: 'ab'  ,!.'q' x

(x,   4$'ab',  4$' ') -: 'ab'  ,     ~x=.2 4$'Esperanto'
(x,   4$'ab',  4$'q') -: 'ab'  ,!.'q'~x
(x, 3 4$'ab', 12$' ') -: 'ab'  ,     ~x=.2 3 4$'Vandermonde matrices'
(x, 3 4$'ab', 12$'q') -: 'ab'  ,!.'q'~x

(x,~  4$(3;4), 4$a: ) -: (3;4) ,      x=.2 4$;:'how now Charlie Brown?'
(x,~  4$(3;4), 4$<9 ) -: (3;4) ,!.(<9)x
(x,~3 4$(3;4),12$a: ) -: (3;4) ,      x=.2 3 4$;:'sigh no more a-shore x'
(x,~3 4$(3;4),12$<9 ) -: (3;4) ,!.(<9)x

(x,   4$(3;4), 4$a: ) -: (3;4) ,      ~x=.2 4$;:'how now Charlie Brown?'
(x,   4$(3;4), 4$<9 ) -: (3;4) ,!.(<9)~x
(x, 3 4$(3;4),12$a: ) -: (3;4) ,      ~x=.2 3 4$;:'sigh no more a-shore x'
(x, 3 4$(3;4),12$<9 ) -: (3;4) ,!.(<9)~x

'domain error' -: 99 99 ,!.'a' etx 2 3 4$123
'domain error' -: 99 99 ,!.(<0)etx 2 3 4$123
'domain error' -: 'ab'  ,!.12  etx 2 3 4$'x'
'domain error' -: 'ab'  ,!.(<0)etx 2 3 4$'x'
'domain error' -: (3;4) ,!.'a' etx 2 3 4$<123
'domain error' -: (3;4) ,!.12  etx 2 3 4$<123


NB. x,"r y --------------------------------------------------------------

cat=: 4 : 'x,y'

'A' (,"1 -: cat"1)&> (3,&.>i.10)$&.><'satrap feudal futile'
'A' (,"1 -: cat"1)&>~(3,&.>i.10)$&.><'supermarine'
((i.10)$&.><'ABCDEFGHI') (,"1 -: cat"1)&>/ (3,&.>i.10)$&.><'oxymoron'
((i.10)$&.><'ABCDEFGHI') (,"1 -: cat"1)&>/~(3,&.>i.10)$&.><'suzerainty'
(<'ABC') (,"_1 -: cat"_1)&> (3,&.>i.10)$&.><'inescapable culpable'
(<'ABC') (,"_1 -: cat"_1)&>~(3,&.>i.10)$&.><'inescapable culpable'

12345 (,"0 -: cat"0) ?3 5 7$1e6
12345 (,"0 -: cat"0)~?3 5 7$1e6
12345 (,"1 -: cat"1) ?3 5 7$1e6
12345 (,"1 -: cat"1)~?3 5 7$1e6
12345 (,"2 -: cat"2) ?3 5 7$1e6
12345 (,"2 -: cat"2)~?3 5 7$1e6
12345 (,"3 -: cat"3) ?3 5 7$1e6
12345 (,"3 -: cat"3)~?3 5 7$1e6

123.4 5 6 (,"0 -: cat"0) o.?3 3 3$1e6
123.4 5 6 (,"0 -: cat"0)~o.?3 3 3$1e6
123.4 5 6 (,"1 -: cat"1) o.?3 3 3$1e6
123.4 5 6 (,"1 -: cat"1)~o.?3 3 3$1e6
123.4 5 6 (,"2 -: cat"2) o.?3 3 3$1e6
123.4 5 6 (,"2 -: cat"2)~o.?3 3 3$1e6
123.4 5 6 (,"3 -: cat"3) o.?3 3 3$1e6
123.4 5 6 (,"3 -: cat"3)~o.?3 3 3$1e6

r=: <"1 ] 4 4#:i.16
f=: 3 : 'xx (,"y -: cat"y) yy'

f&>r [ xx=:    ?  2 3 4$2   [ yy=:    ?  2 3 4$2
f&>r [ xx=:a.{~?  2 3 4$256 [ yy=:a.{~?  2 3 4$256
f&>r [ xx=:    ?  2 3 4$100 [ yy=:    ?  2 3 4$100
f&>r [ xx=:o.  ?  2 3 4$100 [ yy=:o.  ?  2 3 4$100
f&>r [ xx=:j./ ?2 2 3 4$100 [ yy=:j./ ?2 2 3 4$100

f&>r [ xx=:    ?  2 3  $2   [ yy=:    ?  2 3 4$2
f&>r [ xx=:a.{~?  2 3  $256 [ yy=:a.{~?  2 3 4$256
f&>r [ xx=:    ?  2 3  $100 [ yy=:    ?  2 3 4$100
f&>r [ xx=:o.  ?  2 3  $100 [ yy=:o.  ?  2 3 4$100
f&>r [ xx=:j./ ?2 2 3  $100 [ yy=:j./ ?2 2 3 4$100

f&>r [ xx=:    ?  2 3 4$2   [ yy=:    ?  2 3  $2
f&>r [ xx=:a.{~?  2 3 4$256 [ yy=:a.{~?  2 3  $256
f&>r [ xx=:    ?  2 3 4$100 [ yy=:    ?  2 3  $100
f&>r [ xx=:o.  ?  2 3 4$100 [ yy=:o.  ?  2 3  $100
f&>r [ xx=:j./ ?2 2 3 4$100 [ yy=:j./ ?2 2 3  $100

f&>r [ xx=:?2               [ yy=:    ?  2 3 4$2
f&>r [ xx=:'A'              [ yy=:a.{~?  2 3 4$256
f&>r [ xx=:?100             [ yy=:    ?  2 3 4$100
f&>r [ xx=:o.?100           [ yy=:o.  ?  2 3 4$100
f&>r [ xx=:j./?2$100        [ yy=:j./ ?2 2 3 4$100

f&>r [ xx=:    ?  2 3 4$2   [ yy=:?2
f&>r [ xx=:a.{~?  2 3 4$256 [ yy=:'B'
f&>r [ xx=:    ?  2 3 4$100 [ yy=:?100
f&>r [ xx=:o.  ?  2 3 4$100 [ yy=:o.?100
f&>r [ xx=:j./ ?2 2 3 4$100 [ yy=:j./?2$100

3.5 (,"0 1 -: cat"0 1) i.5 0
3.5 (,"1 0 -: cat"1 0)~i.5 0
3.5 (,"0 2 -: cat"0 2) i.3 0 5
3.5 (,"2 0 -: cat"2 0)~i.3 0 5

(i.0 10)  -: (i.0 3),"1 i.0 7
(i.0 8 3) -: (i.0 3),"_1 i.0 7 3

n=:11
test=. 4 : '((n,x)$''x'') (,"1 -: cat"1) (n,y)$''y'''

test"0/~i.20

4!:55 ;:'cat f n r t test x xx y yy'