IF YOU CAN SEE THIS go to http://www.cs.cornell.edu/Info/People/sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
prime divs mul via intseg1a 1. p : 2. prime(p)
3. a : b:, e:({a..b}).
a<bp | (i:{a..b}. e(i)) (i:{a..b}. p | e(i))
By:
{Use induction over size of the index set }
k:, b:.
b-a = k (e:({a..b}). a<bp | (i:{a..b}. e(i)) (i:{a..b}. p | e(i)))
Asserted