| Step | Hyp | Ref | Expression | 
						
							| 1 |  | orc |  |-  ( -. ph -> ( -. ph \/ ps ) ) | 
						
							| 2 |  | olc |  |-  ( ps -> ( -. ph \/ ps ) ) | 
						
							| 3 | 1 2 | ja |  |-  ( ( ph -> ps ) -> ( -. ph \/ ps ) ) | 
						
							| 4 | 3 | imim1i |  |-  ( ( ( -. ph \/ ps ) -> ( ch \/ ( th \/ ta ) ) ) -> ( ( ph -> ps ) -> ( ch \/ ( th \/ ta ) ) ) ) | 
						
							| 5 |  | pm2.24 |  |-  ( th -> ( -. th -> ph ) ) | 
						
							| 6 |  | idd |  |-  ( th -> ( ph -> ph ) ) | 
						
							| 7 | 5 6 | jaod |  |-  ( th -> ( ( -. th \/ ph ) -> ph ) ) | 
						
							| 8 | 7 | com12 |  |-  ( ( -. th \/ ph ) -> ( th -> ph ) ) | 
						
							| 9 |  | pm1.5 |  |-  ( ( -. ( ph -> ps ) \/ ( ch \/ ( th \/ ta ) ) ) -> ( ch \/ ( -. ( ph -> ps ) \/ ( th \/ ta ) ) ) ) | 
						
							| 10 |  | pm2.3 |  |-  ( ( -. ( ph -> ps ) \/ ( th \/ ta ) ) -> ( -. ( ph -> ps ) \/ ( ta \/ th ) ) ) | 
						
							| 11 |  | pm1.5 |  |-  ( ( -. ( ph -> ps ) \/ ( ta \/ th ) ) -> ( ta \/ ( -. ( ph -> ps ) \/ th ) ) ) | 
						
							| 12 |  | pm2.21 |  |-  ( -. ph -> ( ph -> ps ) ) | 
						
							| 13 |  | jcn |  |-  ( th -> ( -. ph -> -. ( th -> ph ) ) ) | 
						
							| 14 | 12 13 | imim12i |  |-  ( ( ( ph -> ps ) -> th ) -> ( -. ph -> ( -. ph -> -. ( th -> ph ) ) ) ) | 
						
							| 15 | 14 | pm2.43d |  |-  ( ( ( ph -> ps ) -> th ) -> ( -. ph -> -. ( th -> ph ) ) ) | 
						
							| 16 | 15 | con4d |  |-  ( ( ( ph -> ps ) -> th ) -> ( ( th -> ph ) -> ph ) ) | 
						
							| 17 |  | imor |  |-  ( ( ( ph -> ps ) -> th ) <-> ( -. ( ph -> ps ) \/ th ) ) | 
						
							| 18 |  | imor |  |-  ( ( ( th -> ph ) -> ph ) <-> ( -. ( th -> ph ) \/ ph ) ) | 
						
							| 19 | 16 17 18 | 3imtr3i |  |-  ( ( -. ( ph -> ps ) \/ th ) -> ( -. ( th -> ph ) \/ ph ) ) | 
						
							| 20 | 19 | orim2i |  |-  ( ( ta \/ ( -. ( ph -> ps ) \/ th ) ) -> ( ta \/ ( -. ( th -> ph ) \/ ph ) ) ) | 
						
							| 21 |  | pm1.5 |  |-  ( ( ta \/ ( -. ( th -> ph ) \/ ph ) ) -> ( -. ( th -> ph ) \/ ( ta \/ ph ) ) ) | 
						
							| 22 | 10 11 20 21 | 4syl |  |-  ( ( -. ( ph -> ps ) \/ ( th \/ ta ) ) -> ( -. ( th -> ph ) \/ ( ta \/ ph ) ) ) | 
						
							| 23 | 22 | orim2i |  |-  ( ( ch \/ ( -. ( ph -> ps ) \/ ( th \/ ta ) ) ) -> ( ch \/ ( -. ( th -> ph ) \/ ( ta \/ ph ) ) ) ) | 
						
							| 24 |  | pm1.5 |  |-  ( ( ch \/ ( -. ( th -> ph ) \/ ( ta \/ ph ) ) ) -> ( -. ( th -> ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 25 | 9 23 24 | 3syl |  |-  ( ( -. ( ph -> ps ) \/ ( ch \/ ( th \/ ta ) ) ) -> ( -. ( th -> ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 26 |  | imor |  |-  ( ( ( ph -> ps ) -> ( ch \/ ( th \/ ta ) ) ) <-> ( -. ( ph -> ps ) \/ ( ch \/ ( th \/ ta ) ) ) ) | 
						
							| 27 |  | imor |  |-  ( ( ( th -> ph ) -> ( ch \/ ( ta \/ ph ) ) ) <-> ( -. ( th -> ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 28 | 25 26 27 | 3imtr4i |  |-  ( ( ( ph -> ps ) -> ( ch \/ ( th \/ ta ) ) ) -> ( ( th -> ph ) -> ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 29 | 4 8 28 | syl2im |  |-  ( ( ( -. ph \/ ps ) -> ( ch \/ ( th \/ ta ) ) ) -> ( ( -. th \/ ph ) -> ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 30 |  | imor |  |-  ( ( ( -. ph \/ ps ) -> ( ch \/ ( th \/ ta ) ) ) <-> ( -. ( -. ph \/ ps ) \/ ( ch \/ ( th \/ ta ) ) ) ) | 
						
							| 31 |  | imor |  |-  ( ( ( -. th \/ ph ) -> ( ch \/ ( ta \/ ph ) ) ) <-> ( -. ( -. th \/ ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 32 | 29 30 31 | 3imtr3i |  |-  ( ( -. ( -. ph \/ ps ) \/ ( ch \/ ( th \/ ta ) ) ) -> ( -. ( -. th \/ ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) | 
						
							| 33 | 32 | imori |  |-  ( -. ( -. ( -. ph \/ ps ) \/ ( ch \/ ( th \/ ta ) ) ) \/ ( -. ( -. th \/ ph ) \/ ( ch \/ ( ta \/ ph ) ) ) ) |