∀ {method : String} {params? : Option Lean.Json.Structured} {method_1 : String}
  {params?_1 : Option Lean.Json.Structured},
  Lean.JsonRpc.Message.notification method params? = Lean.JsonRpc.Message.notification method_1 params?_1 →
    method = method_1 ∧ params? = params?_1