Def P & Q == PQ

is mentioned by

Thm* 'a,'b:S, b:'b, a:'a, y:'b, x:'a. <x,y> = <a,b>  x = a & y = b

[pair_eq]

In prior sections: core int 1 bool 1 hol hol bool fun 1

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