# /home/nahaj/public_html/logic/systems/pc-alt.txt
# Transformation rules.
pc-alt
Alternate PC basis
US
Uniform Substitution
p
MP
Modus Ponens
p
(OR (NOT p) q)
q
# initial axioms.
(OR (NOT (OR p p)) p)
Axiom 1
(OR (NOT q) (OR p q))
Axiom 2
(OR (NOT (OR p q)) (OR q p))
Axiom 3
(IMP (IMP q r) (IMP (OR p q) (OR p r)))
Axiom 4