a:`a`b`c!10 20 30
!a
?a
b:0 1 2!20 30 40
!b
?b
b~20 30 40
!!10 20 30
1 2,3 4 5
(`a`b`c!10 20 30),`b`c!40 50
0N_0N 0 1 2!10 20 30 40
((,0N)!,10),20 30 40
((,0N)!,10),0 1 2!20 30 40
10 20 30~0 1 2!10 20 30

/ listhood:  (h/t john earnest)
(!b)~!!b
b~?:/b
b~?b
