Statement
Lemma
The k-colourings problem (graphs) is in NP.
Proof
The problem is of the correct from for a search problem as you either have to provide a proper vertex k-colouring or you have to say no such colouring exists.
If you are given
Lemma
The k-colourings problem (graphs) is in NP.
The problem is of the correct from for a search problem as you either have to provide a proper vertex k-colouring or you have to say no such colouring exists.
If you are given