math-nli: Output if sentence 2 Entails statement 1 or Contradicts statement 1 - 
sentence 1: Steven had some Watch. Adam gave him 6 more. Now Steven has 26 Watch. 
sentence 2:  Steven had 21 Watch at first.
<equate> (26 - 6, 21)
Steven had some Watch. Adam gave him 6 more. Now Steven has 26 Watch. 
 Steven had 21 Watch at first.