Blake2b.sigma: def of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/spec/crypto/blake/blake2b.bend as Blake2b
Lines 64-77 of bend-collections-laws-crypto@1.0.0.0/spec/crypto/blake/blake2b.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/blake/blake2b.bend&start_line=64&end_line=77

import Base

# RFC 7693 section 2.7: the message word schedule SIGMA[r].
def sigma(r: Nat) -> List<&2,Nat>:
  match r:
    case 0n: [0n,1n,2n,3n,4n,5n,6n,7n,8n,9n,10n,11n,12n,13n,14n,15n]
    case 1n: [14n,10n,4n,8n,9n,15n,13n,6n,1n,12n,0n,2n,11n,7n,5n,3n]
    case 2n: [11n,8n,12n,0n,5n,2n,15n,13n,10n,14n,3n,6n,7n,1n,9n,4n]
    case 3n: [7n,9n,3n,1n,13n,12n,11n,14n,2n,6n,5n,10n,4n,0n,15n,8n]
    case 4n: [9n,0n,5n,7n,2n,4n,10n,15n,14n,1n,11n,12n,6n,8n,3n,13n]
    case 5n: [2n,12n,6n,10n,0n,11n,8n,3n,4n,13n,7n,5n,15n,14n,1n,9n]
    case 6n: [12n,5n,1n,15n,14n,13n,4n,10n,0n,7n,6n,3n,9n,2n,8n,11n]
    case 7n: [13n,11n,7n,14n,12n,1n,3n,9n,5n,0n,15n,4n,8n,6n,2n,10n]
    case 8n: [6n,15n,14n,9n,11n,3n,0n,8n,12n,2n,13n,7n,1n,4n,10n,5n]
    case 9n: [10n,2n,8n,4n,7n,6n,1n,5n,15n,11n,9n,14n,3n,12n,13n,0n]
    case _: []

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat