Bendtorch.OptState.split: def of bendtorch@1.3.0.0
Import: import bendtorch@1.3.0.0/main.bend as Bendtorch
Lines 78-87 of bendtorch@1.3.0.0/main.bend: https://jend.leeeet.dev/read.txt?path=bendtorch@1.3.0.0/main.bend&start_line=78&end_line=87

import Base

# A packed tree splits at its node; a part not yet stepped splits into two such parts. A leaf belongs to one matrix and
# is never split (it goes to the left, the right side starts empty).
def OptState.split(-A: Type, -B: Type, st: OptState<Two<A, B>>) -> Two<OptState<A>, OptState<B>>:
  match st:
    case NoMom{}: Two{NoMom{}, NoMom{}}
    case OneMom{Two{a, b}}: Two{OneMom{a}, OneMom{b}}
    case TwoMom{Two{a, b}, Two{c, d}}: Two{TwoMom{a, c}, TwoMom{b, d}}
    case Packed{PNode{a, b}}: Two{Packed{a}, Packed{b}}
    case Packed{PNew{+f}}: Two{Packed{PNew{f}}, Packed{PNew{f}}}
    case Packed{t}: Two{Packed{t}, Packed{PNew{False{}}}}

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/main.bend&name=OptState
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/main.bend&name=PTree
  https://jend.leeeet.dev/definition.txt?path=bendtorch@1.3.0.0/main.bend&name=Two