15.
(1) All ducks in this village, that are branded ‘B,’ belong to Mrs. Bond;
(2) Ducks in this village never wear lace collars, unless they are branded ‘B’;
(3) Mrs. Bond has no gray ducks in this village.
Univ. “ducks in this village”; a = belonging to Mrs. Bond; b = branded ‘B’; c = gray; d = wearing lace-collars.
16.
(1) All the old articles in this cupboard are cracked;
(2) No jug in this cupboard is new;
(3) Nothing in this cupboard, that is cracked, will hold water.
Univ. “things in this cupboard”; a = able to hold water; b = cracked; c = jugs; d = old.
17.
(1) All unripe fruit is unwholesome;
(2) All these apples are wholesome;
(3) No fruit, grown in the shade, is ripe.
Univ. “fruit”; a = grown in the shade; b = ripe; c = these apples; d = wholesome.