I'm currently studying a proof in graph theory and it says:
'Suppose that what we want to prove is true for 1,2,3, ..., n-1. We will prove that it holds for n'. Is this a legit form of induction?
Usually, in the induction proofs I encountered until now it was something like. Suppose it's true for n, then we will prove it's true for n +1 or suppose it's true for n-1, we will prove that it's true for n but this seems to be another form induction than the one mentioned above.
Thanks for any help.