| Step | Hyp | Ref | Expression | 
						
							| 1 |  | s2eqd.1 |  |-  ( ph -> A = N ) | 
						
							| 2 |  | s2eqd.2 |  |-  ( ph -> B = O ) | 
						
							| 3 |  | s3eqd.3 |  |-  ( ph -> C = P ) | 
						
							| 4 |  | s4eqd.4 |  |-  ( ph -> D = Q ) | 
						
							| 5 |  | s5eqd.5 |  |-  ( ph -> E = R ) | 
						
							| 6 |  | s6eqd.6 |  |-  ( ph -> F = S ) | 
						
							| 7 | 1 2 3 4 5 | s5eqd |  |-  ( ph -> <" A B C D E "> = <" N O P Q R "> ) | 
						
							| 8 | 6 | s1eqd |  |-  ( ph -> <" F "> = <" S "> ) | 
						
							| 9 | 7 8 | oveq12d |  |-  ( ph -> ( <" A B C D E "> ++ <" F "> ) = ( <" N O P Q R "> ++ <" S "> ) ) | 
						
							| 10 |  | df-s6 |  |-  <" A B C D E F "> = ( <" A B C D E "> ++ <" F "> ) | 
						
							| 11 |  | df-s6 |  |-  <" N O P Q R S "> = ( <" N O P Q R "> ++ <" S "> ) | 
						
							| 12 | 9 10 11 | 3eqtr4g |  |-  ( ph -> <" A B C D E F "> = <" N O P Q R S "> ) |