How can a theory be decidable but incomplete?
50099
Example of incomplete, but decidable theory, and of complete and undecidable theory, question
113344
How do we prove that something is unprovable?
61489
Is there a statement whose undecidability is undecidable?
22584
Can we prove that a statement cannot be proved?
149955
Are runtime bounds in P decidable? (answer: no)
63618
Can all ordinals be obtained by taking successors and countable limits?
40643
Recognizable vs Decidable
76597
Examples of provably${}^n$ unprovable statements
112899
Final theory in Physics: a mathematical existence proof?
139992
Is power-associativity finitely axiomatizable?
126713
Strong induction and vacuous truth
122684
How do you prove Well-Ordering without Mathematical Induction? (and vice-versa)
113957
Why is it possible to conclude everything from a false statement?
3663
Finding counterexamples in elementary set theory.
136052
Could it be that Goldbach conjecture is undecidable?
113342
Confusion of the decidability of $(N,s)$
86893
Show that it is impossible to list the rational numbers in increasing order