IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
member filter2 1. T : Type
2. P : T 3. T List
4. u : T 5. v : T List
6. x:T. (x filter(P;v)) (xv) & P(x)
x:T.
(x if P(u) [u / filter(P;v)] else filter(P;v) fi) (x [u / v]) & P(x)
By:
SplitOnConclITE
THEN
RWO Thm*l:T List, a,x:T. (x [a / l]) x = a (xl) 0