Full Idea
A truth assignment is a function from propositions to the set {T,F}. We will think of T and F as the truth values true and false, but for our purposes all we need to assume about the identity of these objects is that they are different from each other.
Gist of Idea
We make a truth assignment to T and F, which may be true and false, but merely differ from one another
Source
José L. Zalabardo (Introduction to the Theory of Logic [2000], §2.4)
Book Reference
Zalabardo,José L.: 'Introduction to the Theory of Logic' [Westview 2000], p.50
A Reaction
Note that T and F are 'objects'. This remark is important in understanding modern logical semantics. T and F can be equated to 1 and 0 in the language of a computer. They just mean as much as you want them to mean.