p.45 #2.3 -- validity
p.53 #2.13
p.77 #3.10 -- TW + arguments
p.62 #2.20 -- proofs in Fitch
p.104 #4.6 + 4.7 -- truth table in Boole
p.113 #4.24 -- taut con
p.117 #4.30 -- taut con in Fitch
Rosen:
p.20 #23 -- duality
p.604 #11, #19
p.623 #7