Return ``x`` + ``y``.

def add(x, y, context=None):
    """
    Return ``x`` + ``y``.

    """
    return _apply_function_in_current_context(
        BigFloat,
        mpfr.mpfr_add,
        (
            BigFloat._implicit_convert(x),
            BigFloat._implicit_convert(y),
        ),
        context,
    )