Examples of complete induction done in class included proving that every number greater than 1 had a prime factorization, every full binary tree has an odd number of nodes (which brought back fond memories of CSC148), chocolate squares, as well as an obligatory postage stamp induction example.
I feel most comfortable with induction now, and I think I can attribute that to the well worded definitions of both flavours of induction. I had not been introduced to such definitions, as most prior to the ones given in 236 (with the exception of 165) were based on the mathematical notation, which I did not find to be too great in clarifying the process in induction. This, I think, is the likely cause of the usual question about induction, "aren't we assuming what we're trying to prove?" As well, on Friday, the princple of well-ordering was introduced, albiet briefly.
1 comment:
Yes, there's a point in the ultra-terse presentation of simple induction where we often say: "Let n be a natural number, and assume P(n)..."
A natural response is "Wait a minute! Isn't the whole point to prove that for all n in N, P(n), and here we are assuming it!"
The tricky distinction is that, in the induction step, we're showing that P(n) implies P(n+1). So we assume a particular P(n), to show it implies its successor.
Post a Comment