| Step | Hyp | Ref | Expression | 
						
							| 1 |  | srngstr.r |  |-  R = ( { <. ( Base ` ndx ) , B >. , <. ( +g ` ndx ) , .+ >. , <. ( .r ` ndx ) , .x. >. } u. { <. ( *r ` ndx ) , .* >. } ) | 
						
							| 2 | 1 | srngstr |  |-  R Struct <. 1 , 4 >. | 
						
							| 3 |  | plusgid |  |-  +g = Slot ( +g ` ndx ) | 
						
							| 4 |  | snsstp2 |  |-  { <. ( +g ` ndx ) , .+ >. } C_ { <. ( Base ` ndx ) , B >. , <. ( +g ` ndx ) , .+ >. , <. ( .r ` ndx ) , .x. >. } | 
						
							| 5 |  | ssun1 |  |-  { <. ( Base ` ndx ) , B >. , <. ( +g ` ndx ) , .+ >. , <. ( .r ` ndx ) , .x. >. } C_ ( { <. ( Base ` ndx ) , B >. , <. ( +g ` ndx ) , .+ >. , <. ( .r ` ndx ) , .x. >. } u. { <. ( *r ` ndx ) , .* >. } ) | 
						
							| 6 | 5 1 | sseqtrri |  |-  { <. ( Base ` ndx ) , B >. , <. ( +g ` ndx ) , .+ >. , <. ( .r ` ndx ) , .x. >. } C_ R | 
						
							| 7 | 4 6 | sstri |  |-  { <. ( +g ` ndx ) , .+ >. } C_ R | 
						
							| 8 | 2 3 7 | strfv |  |-  ( .+ e. X -> .+ = ( +g ` R ) ) |