Define a hypothesis rectangle h[a,b,c,d], and initialise it to [-,-,-,-]

for each + example e

{

if e is not within h

{

enlarge h to be just big enough to hold e (and all previous e's)

} else { do nothing: h already contains e } }

If we step through this with your training set, we get:

0. h = [-,-,-,-] // initial value

1. h = [4,4,4,4] // (4,4) is not in h: change h so it just contains (4,4)

2. h = [4,5,3,4] // (5,3) is not in h, so enlarge h to fit (4,4) and (5,3)

3. h = [4,6,3,5] // (6,5) is not in h, so enlarge again

4. // no more positive examples left, so we're done.