Exercise: Translation and Validity in Quantifier Logic

Selected Solutions

Translate and test for validity:

2.  Clams and oysters are edible mollusks.  Therefore, clams are edible.

Cx: x is a clam

Ox: x is an oyster

Ex: x is edible

Mx: x is a mollusk

(x)((Cx v Ox) ⊃  (Mx & Ex)) /// (x)(Cx ⊃ Ex)

7.    Snails and insects are edible only if properly cooked.  Insects are never properly cooked.  Therefore, insects are not edible.

Sx: x is a snail

Ix: x is an insect

Ex: x is edible

Px: x is properly cooked

(x)((Sx v Ix) ⊃ (Ex ⊃ Cx)), (x)(Ix ⊃ ~Cx) /// (x)(Ix ⊃ ~Ex)