IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
append split2113 1. T : Type
2. L : T List
3. P : ||L||Prop
4. x:||L||. Dec(P(x))
5. i,j:||L||. P(i) i<jP(j)
6. i : ||L||
7. P(i)
8. j:i. P(j)
9. i@0 : ||L||
10. ||firstn(i;L)||i@0 P(i@0)
By:
RWO Thm*as:A List, n:{0...||as||}. ||firstn(n;as)|| = n -1
THEN
Decide (i@0 = i)