Function extern_spec_TryFrom_u128_i128_try_from 

pub fn extern_spec_TryFrom_u128_i128_try_from(
    value: u128,
) -> Result<i128, TryFromIntError>

extern spec for i128::try_from

This is not a real function: its only use is for documentation.

ghost

ensures

match result { Ok(val) => val@ == value@, Err(_) => value@ > Self::MAX@ }