def back

bend-lawful-stdlib@0.1.0.0 · src/sim.bend:27

import Base
import bend-lawful-stdlib@0.1.0.0/src/class.bend as C

27def back(~P: Data, ~g: C.Group<P>, ~F: P -> P, s: State<P>) -> State<P>:
28  match s:
29    case State{x, +w}:
30      +x0 = C.Group.sub(P, g, x, w)
31      State{x0, C.Group.sub(P, g, w, F(x0))}