Bendtorch.ts_add: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/main.bend as Bendtorch
Lines 3112-3118 of bendtorch@1.3.0.0/main.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/main.bend&start_line=3112&end_line=3118

import Base

# the sum of a[0] .. a[m-1] as a balanced tree of additions (pairwise summation), in place: each pass adds neighbours
# (a[i] = a[2i] + a[2i+1], an odd last one carried), until one number is left. Its rounding error grows with log2(m),
# not m, as in PyTorch's cascade sum: a running sum of 295k squares was 1e-4 off (NOTES, 2026-10-17)
def ts_add(+i: U32, +x: F32, r: Array<F32> & F32) -> Array<F32>:
  match r:
    case Tuple{a, +y}:
      Array.set(F32, a, i, (x + y : F32))

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Array.set
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32