| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							summo.1 | 
							 |-  F = ( k e. ZZ |-> if ( k e. A , B , 0 ) )  | 
						
						
							| 2 | 
							
								
							 | 
							summo.2 | 
							 |-  ( ( ph /\ k e. A ) -> B e. CC )  | 
						
						
							| 3 | 
							
								
							 | 
							sumrb.4 | 
							 |-  ( ph -> M e. ZZ )  | 
						
						
							| 4 | 
							
								
							 | 
							sumrb.5 | 
							 |-  ( ph -> N e. ZZ )  | 
						
						
							| 5 | 
							
								
							 | 
							sumrb.6 | 
							 |-  ( ph -> A C_ ( ZZ>= ` M ) )  | 
						
						
							| 6 | 
							
								
							 | 
							sumrb.7 | 
							 |-  ( ph -> A C_ ( ZZ>= ` N ) )  | 
						
						
							| 7 | 
							
								4
							 | 
							adantr | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> N e. ZZ )  | 
						
						
							| 8 | 
							
								
							 | 
							seqex | 
							 |-  seq M ( + , F ) e. _V  | 
						
						
							| 9 | 
							
								
							 | 
							climres | 
							 |-  ( ( N e. ZZ /\ seq M ( + , F ) e. _V ) -> ( ( seq M ( + , F ) |` ( ZZ>= ` N ) ) ~~> C <-> seq M ( + , F ) ~~> C ) )  | 
						
						
							| 10 | 
							
								7 8 9
							 | 
							sylancl | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> ( ( seq M ( + , F ) |` ( ZZ>= ` N ) ) ~~> C <-> seq M ( + , F ) ~~> C ) )  | 
						
						
							| 11 | 
							
								2
							 | 
							adantlr | 
							 |-  ( ( ( ph /\ N e. ( ZZ>= ` M ) ) /\ k e. A ) -> B e. CC )  | 
						
						
							| 12 | 
							
								
							 | 
							simpr | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> N e. ( ZZ>= ` M ) )  | 
						
						
							| 13 | 
							
								1 11 12
							 | 
							sumrblem | 
							 |-  ( ( ( ph /\ N e. ( ZZ>= ` M ) ) /\ A C_ ( ZZ>= ` N ) ) -> ( seq M ( + , F ) |` ( ZZ>= ` N ) ) = seq N ( + , F ) )  | 
						
						
							| 14 | 
							
								6 13
							 | 
							mpidan | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> ( seq M ( + , F ) |` ( ZZ>= ` N ) ) = seq N ( + , F ) )  | 
						
						
							| 15 | 
							
								14
							 | 
							breq1d | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> ( ( seq M ( + , F ) |` ( ZZ>= ` N ) ) ~~> C <-> seq N ( + , F ) ~~> C ) )  | 
						
						
							| 16 | 
							
								10 15
							 | 
							bitr3d | 
							 |-  ( ( ph /\ N e. ( ZZ>= ` M ) ) -> ( seq M ( + , F ) ~~> C <-> seq N ( + , F ) ~~> C ) )  | 
						
						
							| 17 | 
							
								2
							 | 
							adantlr | 
							 |-  ( ( ( ph /\ M e. ( ZZ>= ` N ) ) /\ k e. A ) -> B e. CC )  | 
						
						
							| 18 | 
							
								
							 | 
							simpr | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> M e. ( ZZ>= ` N ) )  | 
						
						
							| 19 | 
							
								1 17 18
							 | 
							sumrblem | 
							 |-  ( ( ( ph /\ M e. ( ZZ>= ` N ) ) /\ A C_ ( ZZ>= ` M ) ) -> ( seq N ( + , F ) |` ( ZZ>= ` M ) ) = seq M ( + , F ) )  | 
						
						
							| 20 | 
							
								5 19
							 | 
							mpidan | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> ( seq N ( + , F ) |` ( ZZ>= ` M ) ) = seq M ( + , F ) )  | 
						
						
							| 21 | 
							
								20
							 | 
							breq1d | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> ( ( seq N ( + , F ) |` ( ZZ>= ` M ) ) ~~> C <-> seq M ( + , F ) ~~> C ) )  | 
						
						
							| 22 | 
							
								3
							 | 
							adantr | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> M e. ZZ )  | 
						
						
							| 23 | 
							
								
							 | 
							seqex | 
							 |-  seq N ( + , F ) e. _V  | 
						
						
							| 24 | 
							
								
							 | 
							climres | 
							 |-  ( ( M e. ZZ /\ seq N ( + , F ) e. _V ) -> ( ( seq N ( + , F ) |` ( ZZ>= ` M ) ) ~~> C <-> seq N ( + , F ) ~~> C ) )  | 
						
						
							| 25 | 
							
								22 23 24
							 | 
							sylancl | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> ( ( seq N ( + , F ) |` ( ZZ>= ` M ) ) ~~> C <-> seq N ( + , F ) ~~> C ) )  | 
						
						
							| 26 | 
							
								21 25
							 | 
							bitr3d | 
							 |-  ( ( ph /\ M e. ( ZZ>= ` N ) ) -> ( seq M ( + , F ) ~~> C <-> seq N ( + , F ) ~~> C ) )  | 
						
						
							| 27 | 
							
								
							 | 
							uztric | 
							 |-  ( ( M e. ZZ /\ N e. ZZ ) -> ( N e. ( ZZ>= ` M ) \/ M e. ( ZZ>= ` N ) ) )  | 
						
						
							| 28 | 
							
								3 4 27
							 | 
							syl2anc | 
							 |-  ( ph -> ( N e. ( ZZ>= ` M ) \/ M e. ( ZZ>= ` N ) ) )  | 
						
						
							| 29 | 
							
								16 26 28
							 | 
							mpjaodan | 
							 |-  ( ph -> ( seq M ( + , F ) ~~> C <-> seq N ( + , F ) ~~> C ) )  |