I wonder to know where you put the constraint

[ajs7270]

I read your paper "Learning to Reason Deductively: Math Word Problem Solving as Complex Relation Extraction".

In Chapter 3.3, The paper discusses the two constraint

1. there does not exist any expression that involve operations applied to the same quantity
2. intermediate results would not be negative

but I can't find these constraints in your code yet.
Can you tell me which part of the code I should refer to?