I have different functions. Each function is able to deal with only one thing. If I have
X3, then, I can fit three different functions to these variables. One function to each pair of these variables
(X2, X3) and
(X1, X3). However, there is method A that only allows fitting one type of function for all pair of variables. That is if I have functions a, b and c. Then, method A allows only fitting a or b or c to all the pairs of variables.
Therefore, I wrote this:
Method A allows fitting only one type of function to all pair of variables.
Someone told me that, I should change it to:
Method A allows fitting only one type of function to each pair of variables.
I think (as I understand) this will change the meaning of my sentence. That is, the new sentence means that method A allows fitting only (but possibly different) function for each pair of variables. In other words, I think the new sentence means I can fit function a to the first pair, function b to the second pair and function c to the third pair. Is my understanding correct?
In contrast to method A, I have a method B which allows fitting different (single) functions to each pair of variables. That is, I can fit 3 different functions, but only one type (a, or b or c) to each pair of variables. Then, I wrote this:
Method B allows fitting different functions for each pair of variables.
He also told me that I should remove the s from functions. Is this correct?