is mentioned by

Def arb == arb('a)	[harb]
Def res_lambda('a;'b;x.P(x);x.f(x)) == x:'a. if P(x) then f(x) else arb('b) fi	[res_lambda]

In prior sections: hol

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