| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mdslmd.1 |  |-  A e. CH | 
						
							| 2 |  | mdslmd.2 |  |-  B e. CH | 
						
							| 3 |  | mdslmd.3 |  |-  C e. CH | 
						
							| 4 |  | mdslmd.4 |  |-  D e. CH | 
						
							| 5 | 3 4 | chjcli |  |-  ( C vH D ) e. CH | 
						
							| 6 | 5 2 1 | chlej1i |  |-  ( ( C vH D ) C_ B -> ( ( C vH D ) vH A ) C_ ( B vH A ) ) | 
						
							| 7 | 3 4 1 | chjjdiri |  |-  ( ( C vH D ) vH A ) = ( ( C vH A ) vH ( D vH A ) ) | 
						
							| 8 | 2 1 | chjcomi |  |-  ( B vH A ) = ( A vH B ) | 
						
							| 9 | 6 7 8 | 3sstr3g |  |-  ( ( C vH D ) C_ B -> ( ( C vH A ) vH ( D vH A ) ) C_ ( A vH B ) ) | 
						
							| 10 | 9 | adantl |  |-  ( ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) -> ( ( C vH A ) vH ( D vH A ) ) C_ ( A vH B ) ) | 
						
							| 11 | 1 3 | chub2i |  |-  A C_ ( C vH A ) | 
						
							| 12 | 1 4 | chub2i |  |-  A C_ ( D vH A ) | 
						
							| 13 | 11 12 | ssini |  |-  A C_ ( ( C vH A ) i^i ( D vH A ) ) | 
						
							| 14 | 10 13 | jctil |  |-  ( ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) -> ( A C_ ( ( C vH A ) i^i ( D vH A ) ) /\ ( ( C vH A ) vH ( D vH A ) ) C_ ( A vH B ) ) ) | 
						
							| 15 | 3 1 | chjcli |  |-  ( C vH A ) e. CH | 
						
							| 16 | 4 1 | chjcli |  |-  ( D vH A ) e. CH | 
						
							| 17 | 1 2 15 16 | mdslmd1i |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( A C_ ( ( C vH A ) i^i ( D vH A ) ) /\ ( ( C vH A ) vH ( D vH A ) ) C_ ( A vH B ) ) ) -> ( ( C vH A ) MH ( D vH A ) <-> ( ( C vH A ) i^i B ) MH ( ( D vH A ) i^i B ) ) ) | 
						
							| 18 | 14 17 | sylan2 |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( ( C vH A ) MH ( D vH A ) <-> ( ( C vH A ) i^i B ) MH ( ( D vH A ) i^i B ) ) ) | 
						
							| 19 |  | id |  |-  ( A MH B -> A MH B ) | 
						
							| 20 |  | inss1 |  |-  ( C i^i D ) C_ C | 
						
							| 21 |  | sstr |  |-  ( ( ( A i^i B ) C_ ( C i^i D ) /\ ( C i^i D ) C_ C ) -> ( A i^i B ) C_ C ) | 
						
							| 22 | 20 21 | mpan2 |  |-  ( ( A i^i B ) C_ ( C i^i D ) -> ( A i^i B ) C_ C ) | 
						
							| 23 | 3 4 | chub1i |  |-  C C_ ( C vH D ) | 
						
							| 24 |  | sstr |  |-  ( ( C C_ ( C vH D ) /\ ( C vH D ) C_ B ) -> C C_ B ) | 
						
							| 25 | 23 24 | mpan |  |-  ( ( C vH D ) C_ B -> C C_ B ) | 
						
							| 26 | 1 2 3 | 3pm3.2i |  |-  ( A e. CH /\ B e. CH /\ C e. CH ) | 
						
							| 27 |  | mdsl3 |  |-  ( ( ( A e. CH /\ B e. CH /\ C e. CH ) /\ ( A MH B /\ ( A i^i B ) C_ C /\ C C_ B ) ) -> ( ( C vH A ) i^i B ) = C ) | 
						
							| 28 | 26 27 | mpan |  |-  ( ( A MH B /\ ( A i^i B ) C_ C /\ C C_ B ) -> ( ( C vH A ) i^i B ) = C ) | 
						
							| 29 | 19 22 25 28 | syl3an |  |-  ( ( A MH B /\ ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) -> ( ( C vH A ) i^i B ) = C ) | 
						
							| 30 |  | inss2 |  |-  ( C i^i D ) C_ D | 
						
							| 31 |  | sstr |  |-  ( ( ( A i^i B ) C_ ( C i^i D ) /\ ( C i^i D ) C_ D ) -> ( A i^i B ) C_ D ) | 
						
							| 32 | 30 31 | mpan2 |  |-  ( ( A i^i B ) C_ ( C i^i D ) -> ( A i^i B ) C_ D ) | 
						
							| 33 | 4 3 | chub2i |  |-  D C_ ( C vH D ) | 
						
							| 34 |  | sstr |  |-  ( ( D C_ ( C vH D ) /\ ( C vH D ) C_ B ) -> D C_ B ) | 
						
							| 35 | 33 34 | mpan |  |-  ( ( C vH D ) C_ B -> D C_ B ) | 
						
							| 36 | 1 2 4 | 3pm3.2i |  |-  ( A e. CH /\ B e. CH /\ D e. CH ) | 
						
							| 37 |  | mdsl3 |  |-  ( ( ( A e. CH /\ B e. CH /\ D e. CH ) /\ ( A MH B /\ ( A i^i B ) C_ D /\ D C_ B ) ) -> ( ( D vH A ) i^i B ) = D ) | 
						
							| 38 | 36 37 | mpan |  |-  ( ( A MH B /\ ( A i^i B ) C_ D /\ D C_ B ) -> ( ( D vH A ) i^i B ) = D ) | 
						
							| 39 | 19 32 35 38 | syl3an |  |-  ( ( A MH B /\ ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) -> ( ( D vH A ) i^i B ) = D ) | 
						
							| 40 | 29 39 | breq12d |  |-  ( ( A MH B /\ ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) -> ( ( ( C vH A ) i^i B ) MH ( ( D vH A ) i^i B ) <-> C MH D ) ) | 
						
							| 41 | 40 | 3expb |  |-  ( ( A MH B /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( ( ( C vH A ) i^i B ) MH ( ( D vH A ) i^i B ) <-> C MH D ) ) | 
						
							| 42 | 41 | adantlr |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( ( ( C vH A ) i^i B ) MH ( ( D vH A ) i^i B ) <-> C MH D ) ) | 
						
							| 43 | 18 42 | bitr2d |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( C MH D <-> ( C vH A ) MH ( D vH A ) ) ) |