OFFSET
0,2
COMMENTS
We define the "inversion of variables", i, by (i.f)(x1,...,xn)=1+f(1+x1,...,1+xn). Note that {i,identity function} is a group. It turns out that if f is a monotone function, then i.f is also a monotone function. f is equivalent to g if f=g or f=i.g.
EXAMPLE
a(1)=2 because m(x)=0,n(x)=1,k(x)=x are the three monotone Boolean functions (of 1 or fewer variables) and m,n are equivalent.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Alan Veliz-Cuba (alanavc(AT)vt.edu), Jun 18 2006
STATUS
approved