| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cantnfs.s |  |-  S = dom ( A CNF B ) | 
						
							| 2 |  | cantnfs.a |  |-  ( ph -> A e. On ) | 
						
							| 3 |  | cantnfs.b |  |-  ( ph -> B e. On ) | 
						
							| 4 |  | oemapval.t |  |-  T = { <. x , y >. | E. z e. B ( ( x ` z ) e. ( y ` z ) /\ A. w e. B ( z e. w -> ( x ` w ) = ( y ` w ) ) ) } | 
						
							| 5 |  | cantnf.c |  |-  ( ph -> C e. ( A ^o B ) ) | 
						
							| 6 |  | cantnf.s |  |-  ( ph -> C C_ ran ( A CNF B ) ) | 
						
							| 7 |  | cantnf.e |  |-  ( ph -> (/) e. C ) | 
						
							| 8 |  | oecl |  |-  ( ( A e. On /\ B e. On ) -> ( A ^o B ) e. On ) | 
						
							| 9 | 2 3 8 | syl2anc |  |-  ( ph -> ( A ^o B ) e. On ) | 
						
							| 10 |  | onelon |  |-  ( ( ( A ^o B ) e. On /\ C e. ( A ^o B ) ) -> C e. On ) | 
						
							| 11 | 9 5 10 | syl2anc |  |-  ( ph -> C e. On ) | 
						
							| 12 |  | ondif1 |  |-  ( C e. ( On \ 1o ) <-> ( C e. On /\ (/) e. C ) ) | 
						
							| 13 | 11 7 12 | sylanbrc |  |-  ( ph -> C e. ( On \ 1o ) ) | 
						
							| 14 | 13 | eldifbd |  |-  ( ph -> -. C e. 1o ) | 
						
							| 15 |  | ssel |  |-  ( ( A ^o B ) C_ 1o -> ( C e. ( A ^o B ) -> C e. 1o ) ) | 
						
							| 16 | 5 15 | syl5com |  |-  ( ph -> ( ( A ^o B ) C_ 1o -> C e. 1o ) ) | 
						
							| 17 | 14 16 | mtod |  |-  ( ph -> -. ( A ^o B ) C_ 1o ) | 
						
							| 18 |  | oe0m |  |-  ( B e. On -> ( (/) ^o B ) = ( 1o \ B ) ) | 
						
							| 19 | 3 18 | syl |  |-  ( ph -> ( (/) ^o B ) = ( 1o \ B ) ) | 
						
							| 20 |  | difss |  |-  ( 1o \ B ) C_ 1o | 
						
							| 21 | 19 20 | eqsstrdi |  |-  ( ph -> ( (/) ^o B ) C_ 1o ) | 
						
							| 22 |  | oveq1 |  |-  ( A = (/) -> ( A ^o B ) = ( (/) ^o B ) ) | 
						
							| 23 | 22 | sseq1d |  |-  ( A = (/) -> ( ( A ^o B ) C_ 1o <-> ( (/) ^o B ) C_ 1o ) ) | 
						
							| 24 | 21 23 | syl5ibrcom |  |-  ( ph -> ( A = (/) -> ( A ^o B ) C_ 1o ) ) | 
						
							| 25 |  | oe1m |  |-  ( B e. On -> ( 1o ^o B ) = 1o ) | 
						
							| 26 |  | eqimss |  |-  ( ( 1o ^o B ) = 1o -> ( 1o ^o B ) C_ 1o ) | 
						
							| 27 | 3 25 26 | 3syl |  |-  ( ph -> ( 1o ^o B ) C_ 1o ) | 
						
							| 28 |  | oveq1 |  |-  ( A = 1o -> ( A ^o B ) = ( 1o ^o B ) ) | 
						
							| 29 | 28 | sseq1d |  |-  ( A = 1o -> ( ( A ^o B ) C_ 1o <-> ( 1o ^o B ) C_ 1o ) ) | 
						
							| 30 | 27 29 | syl5ibrcom |  |-  ( ph -> ( A = 1o -> ( A ^o B ) C_ 1o ) ) | 
						
							| 31 | 24 30 | jaod |  |-  ( ph -> ( ( A = (/) \/ A = 1o ) -> ( A ^o B ) C_ 1o ) ) | 
						
							| 32 | 17 31 | mtod |  |-  ( ph -> -. ( A = (/) \/ A = 1o ) ) | 
						
							| 33 |  | elpri |  |-  ( A e. { (/) , 1o } -> ( A = (/) \/ A = 1o ) ) | 
						
							| 34 |  | df2o3 |  |-  2o = { (/) , 1o } | 
						
							| 35 | 33 34 | eleq2s |  |-  ( A e. 2o -> ( A = (/) \/ A = 1o ) ) | 
						
							| 36 | 32 35 | nsyl |  |-  ( ph -> -. A e. 2o ) | 
						
							| 37 | 2 36 | eldifd |  |-  ( ph -> A e. ( On \ 2o ) ) | 
						
							| 38 | 37 13 | jca |  |-  ( ph -> ( A e. ( On \ 2o ) /\ C e. ( On \ 1o ) ) ) |