(<=>
(cousin ?P1 ?P2)
(and
(exists (?G1 ?G2)
(and
(grandmother ?P1 ?G1)
(grandfather ?P1 ?G2)
(grandmother ?P2 ?G1)
(grandfather ?P2 ?G2)))
(not
(exists (?M ?F)
(and
(mother ?P1 ?M)
(father ?P1 ?F)
(mother ?P2 ?M)
(father ?P2 ?F)))))) |
Mid-level-ontology.kif 25379-25394 |
All of the following hold: (1) X (2) Y are cousins if (3) only if there exist Z (4) W such that the grandmother of X is Z (5) the grandfather of X is W (6) the grandmother of Y is Z (7) the grandfather of Y is W (8) there don't exist V (9) U such that V is a mother of X (10) U is a father of X (11) V is a mother of Y (12) U is a father of Y |
