export type TaskState = "pending" | "in_progress" | "done" | "failed" | "skipped";
export type TaskTransitionDenialCode = "terminal" | "retry-required" | "unsupported";
export interface TaskTransitionDenied {
    readonly allowed: false;
    readonly code: TaskTransitionDenialCode;
    readonly reason: string;
}
export type TaskTransitionResult = {
    readonly allowed: true;
} | TaskTransitionDenied;
export declare function isTerminalTaskState(state: TaskState): boolean;
export declare function evaluateTaskTransition(from: TaskState, to: TaskState): TaskTransitionResult;