Def P  Q == (P  Q) & (P  Q)

is mentioned by

Thm* as:A List. as = nil  ||as||1	[length_of_not_nil]
Thm* as:T List. null(as)  as = nil	[assert_of_null]

In prior sections: core fun 1 well fnd int 1 bool 1 int 2

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