Jesse Rappaport
Course slides for Professor Rappaport
Conjunction
p
q
_______
p & q
p & q
__________
p
(p -> r) & (q V s)
__________
q V s
Simplification
p
__________
p V q
p
__________
p V (r & s)
Addition
Modus Ponens
p -> q
p
_______
q
Modus Tollens
p -> q
~q
_______
~p
Proof 1
PREMISES:
(p & q) & (r & (s & t))
CONCLUSION:
s
1. (p & q) & (r & (s & t)) PREMISE
2. r & (s & t) SIMPLIFICATION (1)
3. s & t SIMPLIFICATION (2)
4. s SIMPLIFICATION (3)
Proof 2
PREMISES:
(p & (q V r)) & (r & (s <-> t))
CONCLUSION:
p & r
1. (p & (q V r)) & (r & (s <-> t)) PREMISE
2. p & (q V r) SIMPLIFICATION (1)
3. p SIMPLIFICATION (2)
4. r & (s <-> t) SIMPLIFICATION (1)
5. r SIMPLIFICATION (4)
6. p & r CONJUNCTION (3, 5)
Proof 3
PREMISES:
(p & q) -> r
p & s
q
CONCLUSION:
r V t
Proof:
1. (p & q) -> r PREMISE
2. p & s PREMISE
3. q PREMISE
4. p SIMPLIFICATION (2)
5. s SIMPLIFICATION (2)
6. p & q CONJUNCTION (3, 4)
7. r MODUS PONENS (1, 6)
8. r V t ADDITION (7)
Proof 4
PREMISES:
p -> (q & r)
~(q & r)
CONCLUSION:
~p & ~(q & r)
Proof:
1. p -> (q & r) PREMISE
2. ~(q & r) PREMISE
3. ~p MODUS TOLLENS (1, 2)
4. ~p & ~(q & r) CONJUNCTION (2, 3)
Proof 5
PREMISES:
p -> q
p & r
s -> ~(q V r)
CONCLUSION:
~s & p
Proof:
1. p -> q PREMISE
2. p & r PREMISE
3. s -> ~(q V r) PREMISE
4. p SIMPLIFICATION (2)
5. r SIMPLIFICATION (2)
6. q V r ADDITION (5)
7. ~s MODUS TOLLENS (3, 6)
8. ~s & p CONJUNCTION (4, 7)
By Jesse Rappaport