[albrewer]

I took a stab at it, there's not enough information to figure out anything more specific:

  from typing import Callable, Any

  def compose(start: Callable[[Any], Any], *args: Callable[[Any], Any] -> Callable[[Any], Any]:
    def helper(x: Any) -> Any:
      for func in reversed(args):
        x = func(x)
      return start(x)
    return helper

[slaymaker1907]

Sure, that's probably as close as you can get, but ideally it would be possible to write a type which guarantees the input functions are compatible as well as knowing what the type is of the returned function.