IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
exist intseg vs iter or13 1. a :
2. b:, P:({a..b}Prop). ba ((i:{a..b}. P(i)) (Or i:{a..b}. P(i)))
3. k:, b:.
3. b-a = k (P:({a..b}Prop). (i:{a..b}. P(i)) (Or i:{a..b}. P(i)))
b:, P:({a..b}Prop). (i:{a..b}. P(i)) (Or i:{a..b}. P(i))