我目前正在使用vuex和typescript，但我的代码中有这个错误，我不知道如何修复它。TS2322: Type '(state: State, exRep: number, exName: string) => void' is not assignable to type 'Mutation '
我的代码：

import { createStore } from "vuex";
import {State} from "./Types";

const store = createStore<State>({
    state() {
        return {

            exercices: []

        }
    },
    mutations: {
        addEx(state: State, exRep: number, exName: string) {
            const exId = checkid()
            state.exercices.push({ "rep": exRep, "name": exName, "id": exId })
        },
        removeEx(state: State, exoId: Number) {
            console.log(exoId)
            state.exercices = state.exercices.filter(obj => obj.id !== exoId)
        }
    }
})
export default store

错误发生在"addEx"突变处