Def pq == if p q else false fi

is mentioned by

Thm* L:MsgA List. ma-is-empty((L)) ~ reduce(M,x. ma-is-empty(M)x;true;L)

[ma-join-list-is-empty]

In prior sections: bool 1 mb list 1 mb list 2 mb event system 4 mb event system 2 mb event system 3

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