Euler's Analysis Infinitorum, Bk.1, art.1 I just started reading Euler's Analysis Infinitorum Book 1 and am already stuck on the first article: a definition of "constant quantity." It reads as follows:


*

*A constant quantity is a determined quantity which always keeps the same value.


For the sake of convenience, call the first phrase in this definition, "a determined quantity," A; and call the second phrase, "which always keeps the same value," B.
My question: Does B include A? In other words, if I tell you that I am talking about a quantity "which always keeps the same value," then is this quantity determined? (I'm assuming that by the word determined, Euler means: known already, or can be known (theoretically or otherwise) from the available data.) I think it is, because a quantity "which always keeps the same value" must:
-Have a value;
-Be something that is unchanging.
In other words, it has a value that is unchanging, and is therefore theoretically well-determined, hence determined.
This would lead me to believe that the definition could be reduced to,


*

*A constant quantity is a quantity which always keeps the same value,


were this not Euler; the fact that it is Euler makes me slightly hesitant in accepting that he would add a redundant word ("determined") to his definition.
Any clarification would be appreciated!
 A: I would suspect it just has to do with translation.
Euler Archive has the original Latin text:

Quantitas constans est quantitas determinata perpetuo eundum valorem
  servans.

Google translates the statement as:

A constant quantity is determined by constantly keeping the same
  value.

I'm not very good with Latin, so I can't verify. I do have friends that know more about it, so I may ask them and update this answer if I learn anything new.
Either way, the particular version you are reading has decided to translate it a bit differently. I wouldn't get too hung up on it as long as you can make out which are the constants in the rest of the book, but I do appreciate your scrutiny.
UPDATE:
A trusted friend from classical studies gave me the following translation:

A consistent/constant quantity is defined as a quantity preserving
  the same value forever.

He said some other things about predicate adjectives and nominatives, but in the end it seems that your idea and Euler's Latin line up.
A: Really, I think a better translation of determinata here is "fixed", and what Euler wrote simply says
A constant quantity is a fixed quantity, always keeping the same value.
