.type Name <: symbol


.decl n ( x : Name )


n("Homer").
n("Marge").
n("Bart").
n("Lisa").
n("Maggie").


.decl r ( x : number )
.output r ()

r(1) :- n(x), n(y), ord(x) < ord(y).
r(2) :- n(x), n(y), ord(x) > ord(y).

