| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdscmnd.y |  |-  Y = ( S Xs_ R ) | 
						
							| 2 |  | prdscmnd.i |  |-  ( ph -> I e. W ) | 
						
							| 3 |  | prdscmnd.s |  |-  ( ph -> S e. V ) | 
						
							| 4 |  | prdsgabld.r |  |-  ( ph -> R : I --> Abel ) | 
						
							| 5 |  | ablgrp |  |-  ( a e. Abel -> a e. Grp ) | 
						
							| 6 | 5 | ssriv |  |-  Abel C_ Grp | 
						
							| 7 |  | fss |  |-  ( ( R : I --> Abel /\ Abel C_ Grp ) -> R : I --> Grp ) | 
						
							| 8 | 4 6 7 | sylancl |  |-  ( ph -> R : I --> Grp ) | 
						
							| 9 | 1 2 3 8 | prdsgrpd |  |-  ( ph -> Y e. Grp ) | 
						
							| 10 |  | ablcmn |  |-  ( a e. Abel -> a e. CMnd ) | 
						
							| 11 | 10 | ssriv |  |-  Abel C_ CMnd | 
						
							| 12 |  | fss |  |-  ( ( R : I --> Abel /\ Abel C_ CMnd ) -> R : I --> CMnd ) | 
						
							| 13 | 4 11 12 | sylancl |  |-  ( ph -> R : I --> CMnd ) | 
						
							| 14 | 1 2 3 13 | prdscmnd |  |-  ( ph -> Y e. CMnd ) | 
						
							| 15 |  | isabl |  |-  ( Y e. Abel <-> ( Y e. Grp /\ Y e. CMnd ) ) | 
						
							| 16 | 9 14 15 | sylanbrc |  |-  ( ph -> Y e. Abel ) |