The Postal Service could, for example, place a Roman numeral in front of each ZIP Code, yielding a code like I-20878-2619.
The postal service would make zip codes better with roman numerals 
mnli hypothesis: The postal service would make zip codes better with roman numerals  premise: The Postal Service could, for example, place a Roman numeral in front of each ZIP Code, yielding a code like I-20878-2619.