TITLE: Predicate vs function
QUESTION [21 upvotes]: In logic, what is the difference between a predicate and a function? 
To be specific, I am just interested in First Order Logic.
Thanks!

REPLY [3 votes]: I would say that : predicate give you true or false based on your input(s).
While, a function gives you an output per your input(s).
So a predicate is a special function gives you only "true" or "false".