Can a later update invalidate an earlier fact?
State makes an answer depend on when you ask. Recording time with a fact lets two different answers describe different moments without contradicting each other.
Read on through a shared source
Why does testing a business rule need a database? →Separate who qualifies for a reminder from whether the reminder can be delivered.Do separate layers really separate concerns? →Placing code in different layers leaves the underlying concepts free to depend on each other. Trace which changes still require coordinated edits.Which choices should an API leave out? →Removing an uncertain feature reduces what clients must learn. Separating tangled concerns reduces how many choices they must consider together.
Compare the passages
Having state in your program is never simple, right?no they don't because facts incorporate time how is