Chacha.inner_block: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/spec/crypto/chacha.bend as Chacha
Lines 56-65 of bend-collections@1.0.0.0/spec/crypto/chacha.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/spec/crypto/chacha.bend&start_line=56&end_line=65

import Base

# inner_block: four column rounds, then four diagonal rounds.
def inner_block(s: List<&2, U32>) -> List<&2, U32>:
  s1 = quarter(s, 0n, 4n, 8n, 12n)
  s2 = quarter(s1, 1n, 5n, 9n, 13n)
  s3 = quarter(s2, 2n, 6n, 10n, 14n)
  s4 = quarter(s3, 3n, 7n, 11n, 15n)
  s5 = quarter(s4, 0n, 5n, 10n, 15n)
  s6 = quarter(s5, 1n, 6n, 11n, 12n)
  s7 = quarter(s6, 2n, 7n, 8n, 13n)
  quarter(s7, 3n, 4n, 9n, 14n)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/spec/crypto/chacha.bend&name=quarter