Def  == Unit+Unit

is mentioned by

Thm* L:MsgA List. ma-is-empty((L))	[ma-is-empty_wf_join]
Thm*	[bool-inhabited]

In prior sections: bool 1 list 1 sqequal 1 rel 1 mb nat mb list 1 mb list 2 mb event system 1 mb event system 2 mb event system 3 mb event system 5

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