(motive : Lean.Expr × Lean.Elab.Tactic.Do.ProofMode.MGoal × Lean.Expr → Sort u_1) →
  (__discr : Lean.Expr × Lean.Elab.Tactic.Do.ProofMode.MGoal × Lean.Expr) →
    ((m : Lean.Expr) →
        (_new_goal : Lean.Elab.Tactic.Do.ProofMode.MGoal) → (prf : Lean.Expr) → motive (m, _new_goal, prf)) →
      motive __discr