Entailment

A set
T
of
sentences
is
satisfiable
if
there
exists
an
interpretation
satisfying
all
sentences
in
I

A set
T
of
sentences
entails
a
formula
F
(symbolically,
I'
=
F)
if
every
interpretation
satisfying
I'
satisfies
the
universal
closure
of
F

Q:
True
or
false?

{3x P(x),
Ix
Q()}
E
Ix(P(x)
A
Q(x))
felse

{¥x
P(x),
Vx
Q(x)}
E
Vx(P(x)
v
Q(x))
rue