class Output<U : Term>(val name: String) {

    private val callbacks: MutableList<suspend (U) -> Boolean> = mutableListOf()

    fun connect(input: Input<out U>) {
        // input.callback is suspend (U) -> Boolean
        this.callbacks.add(input.callback)
    }

    suspend fun yield(term: U) {
        callbacks.forEach {
            it(term)
        }
    }
}