Solutions to Chapter 29 Ambiguity

Practice exercises

A. Each of the following sentences is ambiguous. Provide a symbolization key for each, and symbolize all readings.

  1. 1.

    No one likes a quitter.

    domain:

    people

    Q(x):

    blank x is a quitter

    L(x,y):

    blank x likes blank y

  2. x(Q(x)y¬L(y,x)) (all quitters are disliked by everyone)
    x(Q(x)y¬L(y,x)) (A specific quitter is disliked by everyone)

  3. 2.

    CSI found only red hair at the scene.

    domain:

    items of evidence

    R(x):

    blank x is red

    H(x):

    blank x is hair

    F(x,y):

    blank x found blank y (at the scene)

    c:

    CSI

  4. x(F(c,x)(R(x)H(x))) (only hair was found, and it’s all red)
    x((F(c,x)H(x))R(x)) (only red hair was found, but possibly other things that aren’t hair)

  5. 3.

    Smith’s murderer hasn’t been arrested.

    domain:

    people

    A(x):

    blank x has been arrested

    M(x,y):

    blank x murdered blank y

    m:

    Smith

  6. x(y(M(y,m)y=x)¬A(x)) (Smith’s murderer has: not been arrested)
    ¬x(y(M(y,m)y=x)A(x)) (It’s not the case that Smith’s murderer has been arrested; in fact there may not be a “Smith’s murderer”.)