math-nli: Output if sentence 2 Entails statement 1 or Contradicts statement 1 - 
sentence 1: Laurence had some watermelon. Joann gave him 3 more. Now Laurence has 23 watermelon. 
sentence 2:  Laurence had 20 watermelons in the beginning.
<equate> (23 - 3, 20)
Laurence had some watermelon. Joann gave him 3 more. Now Laurence has 23 watermelon. 
 Laurence had 20 watermelons in the beginning.