The origin of the term "predicate" to denote a Boolean function?

Question

In the schema, the term "predicate" is used as follows:

A predicate is a procedure that always returns a boolean value (#t or #f).

Why does a schema use a predicate to denote such a function? And if the use comes from the previous language, what was the motivation for choosing this term in the first place?

Answer 1

Well, this comes from mathematical logic, as Wikipedia says that a predicate is a fundamental concept in first-order logic. In each "implementation" of logic, a predicate is a sentence that is either true or false, so it fits very well into programming languages.