Indirect and Conditional Proof strategies

Instructions: use any/all 18 rules, as well as Indirect and Conditional Proof strategies to solve these practice problems.

 

  1. (~a V c) & (a V b)
  2. (b & e) –> d
  3. e
    _________________
    c V d

 

 

 

  1. (a V b) & (c V d) (HINT: try IP inside CP)
  2. a –> (e –> (c & d))
  3. c <–> ~d

______________________
e –> b

 

 

  1. (q & ~p) V (~r & q)
  2. ((~p –> s) & (~t –> r)) V (p & r)
  3. (q V p) –> ~t

_______________________

s

 

 

  1. ~(~q <–> p)
  2. ~r –> (p V q)
  3. p –> ~q

_____________________

r