## Natural Language Toolkit: background1.fol
##
## Illustration of simple knowledge base for use with inference tools.
## To accompany sem4.fcfg
##
## Author: Ewan Klein <ewan@inf.ed.ac.uk> 
## URL: <http://nltk.sourceforge.net>
## For license information, see LICENSE.TXT

all x. (boxerdog(x) -> dog(x))
all x. (boxer(x) -> person(x))

all x. (-(dog(x) & person(x)))

all x. (married(x) <-> exists y. marry(x,y)) 
all x. (bark(x) -> dog(x))

all x. all y. (marry(x,y) -> (person(x) & person(y)))

(-(Vincent = Mia))
(-(Vincent = Fido))
(-(Mia = Fido))