a := [1,2,3,4] ----> list(4)
a1 := a[1:2] ----> list(1)
1
every write(!a1) ----> none
a2 := a[3:0] ----> list(2)
3
4
every write(!a2) ----> none
a4 := a[2:2] ----> list(0)
every write(!a4) ----> none
a5 := a[0-:2] ----> list(2)
3
4
every write(!a5) ----> none
a3 := a[0:3] ----> list(2)
3
4
every write(!a3) ----> none
Run-time error 101 at line 20 in expr42.icn
integer expected
offending value: &null