| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pm1.4 |  |-  ( ( ph \/ ch ) -> ( ch \/ ph ) ) | 
						
							| 2 | 1 | ord |  |-  ( ( ph \/ ch ) -> ( -. ch -> ph ) ) | 
						
							| 3 |  | pm4.83 |  |-  ( ( ( ch -> ph ) /\ ( -. ch -> ph ) ) <-> ph ) | 
						
							| 4 | 3 | biimpi |  |-  ( ( ( ch -> ph ) /\ ( -. ch -> ph ) ) -> ph ) | 
						
							| 5 | 2 4 | sylan2 |  |-  ( ( ( ch -> ph ) /\ ( ph \/ ch ) ) -> ph ) | 
						
							| 6 | 5 | ex |  |-  ( ( ch -> ph ) -> ( ( ph \/ ch ) -> ph ) ) | 
						
							| 7 | 6 | anim1d |  |-  ( ( ch -> ph ) -> ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) ) | 
						
							| 8 |  | orc |  |-  ( ph -> ( ph \/ ch ) ) | 
						
							| 9 | 8 | anim1i |  |-  ( ( ph /\ ( ps \/ ch ) ) -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) | 
						
							| 10 | 7 9 | jctir |  |-  ( ( ch -> ph ) -> ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) /\ ( ( ph /\ ( ps \/ ch ) ) -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) ) ) | 
						
							| 11 |  | olc |  |-  ( ch -> ( ph \/ ch ) ) | 
						
							| 12 |  | olc |  |-  ( ch -> ( ps \/ ch ) ) | 
						
							| 13 | 11 12 | jca |  |-  ( ch -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) | 
						
							| 14 |  | simpl |  |-  ( ( ph /\ ( ps \/ ch ) ) -> ph ) | 
						
							| 15 | 13 14 | imim12i |  |-  ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) -> ( ch -> ph ) ) | 
						
							| 16 | 15 | adantr |  |-  ( ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) /\ ( ( ph /\ ( ps \/ ch ) ) -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) ) -> ( ch -> ph ) ) | 
						
							| 17 | 10 16 | impbii |  |-  ( ( ch -> ph ) <-> ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) /\ ( ( ph /\ ( ps \/ ch ) ) -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) ) ) | 
						
							| 18 |  | dfbi2 |  |-  ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) <-> ( ph /\ ( ps \/ ch ) ) ) <-> ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) -> ( ph /\ ( ps \/ ch ) ) ) /\ ( ( ph /\ ( ps \/ ch ) ) -> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) ) ) | 
						
							| 19 |  | ordir |  |-  ( ( ( ph /\ ps ) \/ ch ) <-> ( ( ph \/ ch ) /\ ( ps \/ ch ) ) ) | 
						
							| 20 | 19 | bicomi |  |-  ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) <-> ( ( ph /\ ps ) \/ ch ) ) | 
						
							| 21 | 20 | bibi1i |  |-  ( ( ( ( ph \/ ch ) /\ ( ps \/ ch ) ) <-> ( ph /\ ( ps \/ ch ) ) ) <-> ( ( ( ph /\ ps ) \/ ch ) <-> ( ph /\ ( ps \/ ch ) ) ) ) | 
						
							| 22 | 17 18 21 | 3bitr2i |  |-  ( ( ch -> ph ) <-> ( ( ( ph /\ ps ) \/ ch ) <-> ( ph /\ ( ps \/ ch ) ) ) ) |