let T be full Tree; :: thesis: for n being non empty Element of NAT
for y being Tuple of n,BOOLEAN st y = 0* n holds
(NumberOnLevel n,T) . ('not' y) = 2 to_power n
A1:
T = {0 ,1} *
by Def2;
let n be non empty Element of NAT ; :: thesis: for y being Tuple of n,BOOLEAN st y = 0* n holds
(NumberOnLevel n,T) . ('not' y) = 2 to_power n
let y be Tuple of n,BOOLEAN ; :: thesis: ( y = 0* n implies (NumberOnLevel n,T) . ('not' y) = 2 to_power n )
assume A2:
y = 0* n
; :: thesis: (NumberOnLevel n,T) . ('not' y) = 2 to_power n
A3:
'not' y in T -level n
by A1, Th11;
len (Rev ('not' y)) =
len ('not' y)
by FINSEQ_5:def 3
.=
n
by FINSEQ_1:def 18
;
then reconsider F = Rev ('not' y) as Tuple of n,BOOLEAN by FINSEQ_2:110;
A4:
Rev ('not' y) = 'not' y
by A2, BINARI_3:10;
thus (NumberOnLevel n,T) . ('not' y) =
(Absval F) + 1
by A3, Def1
.=
((2 to_power n) - 1) + 1
by A2, A4, BINARI_3:8
.=
2 to_power n
; :: thesis: verum