Def ||as|| == Case of as; nil  0 ; a.as'  ||as'||+1  (recursive)

is mentioned by

Thm* x:T, l:T List, i:||l||. [x / l][(i+1)] ~ l[i]

[select_cons_tl_sq]

In prior sections: list 1

Try larger context: MarkB generic IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html