I wonder if I have to use a, or the when I introduce two assumptions in an academic paper.
For example, in an introduction section of an article it tells us that there are two assumptions that the authors will discuss in the section 3 and 4 respectively.
Section 3 investigates sensitivity to one of the methodology's major assumptions:
Dirichlet distribution of the shape frailty.
Section 4 investigates a (OR) the second major assumption:
that size and shape frailty variables are statistically independent.
- Should they use a or the for “second assumption”?