∀ (exts : Array (Lean.Meta.Grind.SolverExtension Lean.Meta.Grind.SolverExtensionState)) (i : ℕ)
  (acc : Lean.Meta.Grind.Action),
  Lean.Meta.Grind.Solvers.mkAction.go✝ exts i acc =
    if h : i < exts.size then Lean.Meta.Grind.Solvers.mkAction.go✝¹ exts (i + 1) (acc.andAlso exts[i].action) else acc