state n>> :> n
state mask>> :> mask
- n m - >fixnum iota [| i |
+ n m - >fixnum <iota> [| i |
i array nth-unsafe
i m + array nth-unsafe
mask state r1>> state r2>> formula :> r
] each
! n m - 1 + n [a,b) [
- m 1 - iota [
+ m 1 - <iota> [
n m - 1 + + >fixnum :> i
i array nth-unsafe
m n - i + array nth-unsafe