| Step | Hyp | Ref | Expression | 
						
							| 0 |  | cnegs |  |-  -us | 
						
							| 1 |  | vx |  |-  x | 
						
							| 2 |  | cvv |  |-  _V | 
						
							| 3 |  | vn |  |-  n | 
						
							| 4 | 3 | cv |  |-  n | 
						
							| 5 |  | cright |  |-  _Right | 
						
							| 6 | 1 | cv |  |-  x | 
						
							| 7 | 6 5 | cfv |  |-  ( _Right ` x ) | 
						
							| 8 | 4 7 | cima |  |-  ( n " ( _Right ` x ) ) | 
						
							| 9 |  | cscut |  |-  |s | 
						
							| 10 |  | cleft |  |-  _Left | 
						
							| 11 | 6 10 | cfv |  |-  ( _Left ` x ) | 
						
							| 12 | 4 11 | cima |  |-  ( n " ( _Left ` x ) ) | 
						
							| 13 | 8 12 9 | co |  |-  ( ( n " ( _Right ` x ) ) |s ( n " ( _Left ` x ) ) ) | 
						
							| 14 | 1 3 2 2 13 | cmpo |  |-  ( x e. _V , n e. _V |-> ( ( n " ( _Right ` x ) ) |s ( n " ( _Left ` x ) ) ) ) | 
						
							| 15 | 14 | cnorec |  |-  norec ( ( x e. _V , n e. _V |-> ( ( n " ( _Right ` x ) ) |s ( n " ( _Left ` x ) ) ) ) ) | 
						
							| 16 | 0 15 | wceq |  |-  -us = norec ( ( x e. _V , n e. _V |-> ( ( n " ( _Right ` x ) ) |s ( n " ( _Left ` x ) ) ) ) ) |