Philosophy 251: Handout #15
XXIV. For each of the following arguments construct
a derivation to prove that the argument is valid.
xRax 
xRxa,
~Rba / ~Raa
x[
yRxy
yRyx ], Raa / Rba
x( Fx
Gx
),
x( Gx
Hx
) /
x( Fx
Hx
).
x( Fx
Gx
),
x( ( Gx v Hx )
Kx ) /
x( Fx
Kx )
x( Fx
Gx
) /
xFx 
xGx
x( ( Fx & Gx )
Hx ) /
x( Fx
Gx ) 
x( Fx
Hx )
- /
x( ~Bx
~Ax )
[ ~
xBx
~
xAx
]
x
yCxy / ( Caa & Cab ) & ( Cba
& Cbb )
x( Ax
Bx),
~Bc / ~Ac
y[( Hy & Fy )
Gy ],
zFz & ~
xKxb /
x( Hx
Gx )
xCx
Ch /
xCx
Ch
x( ~Ax
Kx ),
y~Ky /
w( Aw v ~Lwf )
z(
Gz & Az ),
y( Cy
~Gy ) /
z( Az & ~Cz )
x[( ~Cxb v Hx )
Lxx ],
y~Lyy /
xCxb
xFx,
zHz / ~
y( ~Fy v ~Hy )
Back
to Syllabus