我们称

we refer to A as B.
e.g
We refer to 'machine learning algorithm' as training a system.
We refer to 'machine learning algorithm' as predictors.

公平竞争

level playing field
e.g
In commerce, a level playing field is a concept about fairness, not that each 
player has an equal chance to get succeed, but that they all play by the same 
set of rules.

ambiguity, 歧义
a vector as an arrow with a direction and magnitude.