Functions mess (recursive anonymous function) in Golang

package main
 
import (
    "fmt"
    "reflect"
)
 
type Num interface{}
 
type List func(...Num) Num
 
func (list List) Apply(a Num) List {
    return func(values ...Num) Num {
        values = append([]Num{a}, values...)
        return list(values...)
    }
}
 
func wrapper(fn Num) List {
    return func(a ...Num) Num{
        return caller(fn, a)
    }
}
 
func caller(fn Num, args []Num) Num {
    var vs []reflect.Value
    for _, arg := range args {
        vs = append(vs, reflect.ValueOf(arg))
    }
    fun := reflect.ValueOf(fn)
    return fun.Call(vs)[0].Interface()
}
 
func mixture(elems []Num, fn Num) List {
    var list List = wrapper(fn)
    for _, elem := range elems {
        list = list.Apply(elem)
    }	
    return list
}
 
func addition(l int, m int, n int, o int) int {
    return l * m + n * o
}
 
func main() {
    fmt.Println(mixture([]Num{1, 2, 3}, addition)(4)) //14
    fmt.Println(mixture([]Num{1, 2, 3, 4}, addition)()) //14
}