help.ts

import { Option, none, some } from 'fp-ts/lib/Option'
import { TaskEither, fromLeft, taskEither } from 'fp-ts/lib/TaskEither'

const a = (): Option<number> => {
  if (Math.random() > 0.5) {
    return none
  }

  return some(1)
}

const b = (): Option<TaskEither<Error, number>> => {
  return a().map(n => {
    if (Math.random() > 0.5) {
      return fromLeft(new Error('very unlucky'))
    }

    return taskEither.of(n)
  })
}

const c = (): TaskEither<Error, Option<TaskEither<Error, number>>> => {
  if (Math.random() > 0.5) {
    return fromLeft(new Error('unlucky'))
  }

  return taskEither.of(b())
}

const x: TaskEither<Error, Option<TaskEither<Error, number>>> = c()

// how to get to this type from x?
const y: TaskEither<Error, Option<number>> = ???