IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html
At:
sfa doc sexprcarsize111 1. A : Type
2. Q : Sexpr(A)Prop
3. s:{s:Sexpr(A)| Q(s) }. Size(s) 1 Size(sexprCar(s))<Size(s)
4. x1 : {s:Sexpr(A)| Q(s) }
5. x2 : {s:Sexpr(A)| Q(s) }
6. Size(Cons(x1;x2)) 1
Size(sexprCar(Cons(x1;x2)))<Size(Cons(x1;x2))