Sha.previous: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/spec/crypto/sha.bend as Sha
Lines 90-92 of bend-collections@1.0.0.0/spec/crypto/sha.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/spec/crypto/sha.bend&start_line=90&end_line=92

import Base

# The FIPS recurrence names prior words by lags 2, 7, 15 and 16.
def previous(history: List<&2, U32>, lag: Nat) -> U32:
  nth(history, Nat.sub(lag, 1n))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  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/sha.bend&name=nth