BendTensors.Vec4.sum: def of bend-tensors@0.0.0.2
Import: import bend-tensors@0.0.0.2/bend_tensors.bend as BendTensors
Lines 84-88 of bend-tensors@0.0.0.2/bend_tensors.bend: https://jend.leeeet.dev/read.txt?path=bend-tensors@0.0.0.2/bend_tensors.bend&start_line=84&end_line=88

import Base

# the sum, as (x0 + x1) + (x2 + x3): every reduction in this file
# pairs its terms the same way, so laws can equate them
def Vec4.sum(v: Vec4) -> F32:
  Vec4{x0, x1, x2, x3} = v
  ((x0 + x1) + (x2 + x3) : F32)

Uses (3):
  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=bend-tensors@0.0.0.2/bend_tensors.bend&name=Vec4