Def x before y  l == [x; y]  l

is mentioned by

Thm* L:T List, i:(||L||-1), a,b:T. Thm* a before b  swap(L;i;i+1)  a before b  L  a = L[(i+1)] & b = L[i]	[l_before_swap]
Thm* l:T List, P:(T), x,y:T. Thm* x before y  filter(P;l)  P(x) & P(y) & x before y  l	[l_before_filter]

In prior sections: mb list 1

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