| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simp3 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> B ~<_ A ) | 
						
							| 2 |  | reldom |  |-  Rel ~<_ | 
						
							| 3 | 2 | brrelex2i |  |-  ( B ~<_ A -> A e. _V ) | 
						
							| 4 |  | djudom2 |  |-  ( ( B ~<_ A /\ A e. _V ) -> ( A |_| B ) ~<_ ( A |_| A ) ) | 
						
							| 5 | 1 3 4 | syl2anc2 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A |_| B ) ~<_ ( A |_| A ) ) | 
						
							| 6 |  | xp2dju |  |-  ( 2o X. A ) = ( A |_| A ) | 
						
							| 7 | 5 6 | breqtrrdi |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A |_| B ) ~<_ ( 2o X. A ) ) | 
						
							| 8 |  | simp1 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> A e. dom card ) | 
						
							| 9 |  | 2onn |  |-  2o e. _om | 
						
							| 10 |  | nnsdom |  |-  ( 2o e. _om -> 2o ~< _om ) | 
						
							| 11 |  | sdomdom |  |-  ( 2o ~< _om -> 2o ~<_ _om ) | 
						
							| 12 | 9 10 11 | mp2b |  |-  2o ~<_ _om | 
						
							| 13 |  | simp2 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> _om ~<_ A ) | 
						
							| 14 |  | domtr |  |-  ( ( 2o ~<_ _om /\ _om ~<_ A ) -> 2o ~<_ A ) | 
						
							| 15 | 12 13 14 | sylancr |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> 2o ~<_ A ) | 
						
							| 16 |  | xpdom1g |  |-  ( ( A e. dom card /\ 2o ~<_ A ) -> ( 2o X. A ) ~<_ ( A X. A ) ) | 
						
							| 17 | 8 15 16 | syl2anc |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( 2o X. A ) ~<_ ( A X. A ) ) | 
						
							| 18 |  | domtr |  |-  ( ( ( A |_| B ) ~<_ ( 2o X. A ) /\ ( 2o X. A ) ~<_ ( A X. A ) ) -> ( A |_| B ) ~<_ ( A X. A ) ) | 
						
							| 19 | 7 17 18 | syl2anc |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A |_| B ) ~<_ ( A X. A ) ) | 
						
							| 20 |  | infxpidm2 |  |-  ( ( A e. dom card /\ _om ~<_ A ) -> ( A X. A ) ~~ A ) | 
						
							| 21 | 20 | 3adant3 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A X. A ) ~~ A ) | 
						
							| 22 |  | domentr |  |-  ( ( ( A |_| B ) ~<_ ( A X. A ) /\ ( A X. A ) ~~ A ) -> ( A |_| B ) ~<_ A ) | 
						
							| 23 | 19 21 22 | syl2anc |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A |_| B ) ~<_ A ) | 
						
							| 24 | 2 | brrelex1i |  |-  ( B ~<_ A -> B e. _V ) | 
						
							| 25 | 24 | 3ad2ant3 |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> B e. _V ) | 
						
							| 26 |  | djudoml |  |-  ( ( A e. dom card /\ B e. _V ) -> A ~<_ ( A |_| B ) ) | 
						
							| 27 | 8 25 26 | syl2anc |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> A ~<_ ( A |_| B ) ) | 
						
							| 28 |  | sbth |  |-  ( ( ( A |_| B ) ~<_ A /\ A ~<_ ( A |_| B ) ) -> ( A |_| B ) ~~ A ) | 
						
							| 29 | 23 27 28 | syl2anc |  |-  ( ( A e. dom card /\ _om ~<_ A /\ B ~<_ A ) -> ( A |_| B ) ~~ A ) |