Def b == if b false else true fi

is mentioned by

Thm* n:. n>0  odd(n) = odd(n-1)	[odd_pos]
Thm* n:. n>0  even(n) = even(n-1)	[even_pos]
Def odd(n) == if n=0 then false else odd(n-1) fi   (recursive)	[odd]
Def even(n) == if n=0 then true else even(n-1) fi   (recursive)	[even]

In prior sections: bool 1 hol hol bool

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