def tie_b4
import bendtorch@1.3.0.0/main.bend as Bendtorchimport Base
2184def tie_b4(-P: Type, -Q: Type, -X: Type, q: Q, gq: Q, r: Bwd<P, X>) -> Bwd<Two<P, Q>, X>:
2185 match r:
2186 case Bwd{p, dx, gp}:
2187 Bwd{Two{p, q}, dx, Two{gp, gq}}