Transfusion · October 14, 2014 14:10
diff --git a/pg63_42_AE1MFC_bryan_kok b/pg63_42_AE1MFC_bryan_kok
 proof

 # Comments like these represent my informal thoughts...
 1     p | q                                           Hypothesis         %  ok                        
 2     q => r                                          Hypothesis         %  ok                        
 3     p & s => t                                      Hypothesis         %  ok                        
 4     ~r                                              Hypothesis         %  ok                        
 5     ~q => u & s                                     Hypothesis         %  ok 

 # Using modus tollens on lines 2 and 4.                       
 6     [ q                                             Assumption         %  ok                        
 7       r                                             ImpE 2,6           %  ok                        
 8       F ]                                           ImpE 4,7           %  ok                        
 9     ~q                                              ImpI 6-8           %  ok 

 # Implication using line 5.                       
 10    u & s                                           ImpE 5,9           %  ok

 # Line 1: p | q and ~q implies p.                        
 11    [ p                                             Assumption         %  ok                        
 12      p ]                                           Hyp 11             %  ok                        
 13    [ q                                             Assumption         %  ok                        
 14      F                                             ImpE 9,13          %  ok                        
 15      p ]                                           FalseE 14          %  ok                        
 16    p                                               OrE 11-12,13-15,1  %  ok
                        
 17    s                                               AndER 10           %  ok                        
 18    p & s                                           AndI 16,17         %  ok                        
 19    t                                               ImpE 3,18          %  ok
	proof

	# Comments like these represent my informal thoughts...
	1 p \| q Hypothesis % ok
	2 q => r Hypothesis % ok
	3 p & s => t Hypothesis % ok
	4 ~r Hypothesis % ok
	5 ~q => u & s Hypothesis % ok

	# Using modus tollens on lines 2 and 4.
	6 [ q Assumption % ok
	7 r ImpE 2,6 % ok
	8 F ] ImpE 4,7 % ok
	9 ~q ImpI 6-8 % ok

	# Implication using line 5.
	10 u & s ImpE 5,9 % ok

	# Line 1: p \| q and ~q implies p.
	11 [ p Assumption % ok
	12 p ] Hyp 11 % ok
	13 [ q Assumption % ok
	14 F ImpE 9,13 % ok
	15 p ] FalseE 14 % ok
	16 p OrE 11-12,13-15,1 % ok

	17 s AndER 10 % ok
	18 p & s AndI 16,17 % ok
	19 t ImpE 3,18 % ok