segmento :: Int -> Int -> [a] -> [a]

   segmento 3 4 [3,4,1,2,7,9,0]  ==  [1,2]
   segmento 3 5 [3,4,1,2,7,9,0]  ==  [1,2,7]
   segmento 5 3 [3,4,1,2,7,9,0]  ==  []

segmento :: Int -> Int -> [a] -> [a]
segmento m n xs = drop (m-1) (take n xs)

from typing import TypeVar

from hypothesis import given
from hypothesis import strategies as st

A = TypeVar('A')

# 1ª definición
def segmento1(m: int, n: int, xs: list[A]) -> list[A]:
    ys = xs[:n]
    if m == 0:
        return ys
    return ys[m - 1:]

# 2ª definición
def segmento2(m: int, n: int, xs: list[A]) -> list[A]:
    if m == 0:
        return xs[:n]
    return xs[m-1:n]

# La propiedad de equivalencia es
@given(st.integers(min_value=0),
       st.integers(min_value=0),
       st.lists(st.integers()))
def test_equiv_segmento(m: int, n: int, xs: list[int]) -> None:
    assert segmento1(m, n, xs) == segmento2(m, n, xs)

# La comprobación es
#    src> poetry run pytest -q segmento_de_una_lista.py
#    1 passed in 0.19s