| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ordi |  |-  ( ( ph \/ ( ps /\ ch ) ) <-> ( ( ph \/ ps ) /\ ( ph \/ ch ) ) ) | 
						
							| 2 | 1 | anbi1i |  |-  ( ( ( ph \/ ( ps /\ ch ) ) /\ ( ps \/ ch ) ) <-> ( ( ( ph \/ ps ) /\ ( ph \/ ch ) ) /\ ( ps \/ ch ) ) ) | 
						
							| 3 |  | wl-df-3mintru2 |  |-  ( cadd ( ph , ps , ch ) <-> if- ( ph , ( ps \/ ch ) , ( ps /\ ch ) ) ) | 
						
							| 4 |  | animorl |  |-  ( ( ps /\ ch ) -> ( ps \/ ch ) ) | 
						
							| 5 |  | wl-ifp4impr |  |-  ( ( ( ps /\ ch ) -> ( ps \/ ch ) ) -> ( if- ( ph , ( ps \/ ch ) , ( ps /\ ch ) ) <-> ( ( ph \/ ( ps /\ ch ) ) /\ ( ps \/ ch ) ) ) ) | 
						
							| 6 | 4 5 | ax-mp |  |-  ( if- ( ph , ( ps \/ ch ) , ( ps /\ ch ) ) <-> ( ( ph \/ ( ps /\ ch ) ) /\ ( ps \/ ch ) ) ) | 
						
							| 7 | 3 6 | bitri |  |-  ( cadd ( ph , ps , ch ) <-> ( ( ph \/ ( ps /\ ch ) ) /\ ( ps \/ ch ) ) ) | 
						
							| 8 |  | df-3an |  |-  ( ( ( ph \/ ps ) /\ ( ph \/ ch ) /\ ( ps \/ ch ) ) <-> ( ( ( ph \/ ps ) /\ ( ph \/ ch ) ) /\ ( ps \/ ch ) ) ) | 
						
							| 9 | 2 7 8 | 3bitr4i |  |-  ( cadd ( ph , ps , ch ) <-> ( ( ph \/ ps ) /\ ( ph \/ ch ) /\ ( ps \/ ch ) ) ) |