| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mdslle1.1 |  |-  A e. CH | 
						
							| 2 |  | mdslle1.2 |  |-  B e. CH | 
						
							| 3 |  | mdslle1.3 |  |-  C e. CH | 
						
							| 4 |  | mdslle1.4 |  |-  D e. CH | 
						
							| 5 | 3 4 1 | lejdiri |  |-  ( ( C i^i D ) vH A ) C_ ( ( C vH A ) i^i ( D vH A ) ) | 
						
							| 6 | 5 | a1i |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( ( C i^i D ) vH A ) C_ ( ( C vH A ) i^i ( D vH A ) ) ) | 
						
							| 7 |  | ssin |  |-  ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) <-> ( A i^i B ) C_ ( C i^i D ) ) | 
						
							| 8 | 7 | bicomi |  |-  ( ( A i^i B ) C_ ( C i^i D ) <-> ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) ) | 
						
							| 9 | 3 4 2 | chlubi |  |-  ( ( C C_ B /\ D C_ B ) <-> ( C vH D ) C_ B ) | 
						
							| 10 | 9 | bicomi |  |-  ( ( C vH D ) C_ B <-> ( C C_ B /\ D C_ B ) ) | 
						
							| 11 | 8 10 | anbi12i |  |-  ( ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) <-> ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) ) | 
						
							| 12 |  | simpr |  |-  ( ( A MH B /\ B MH* A ) -> B MH* A ) | 
						
							| 13 | 1 3 | chub2i |  |-  A C_ ( C vH A ) | 
						
							| 14 | 1 4 | chub2i |  |-  A C_ ( D vH A ) | 
						
							| 15 | 13 14 | ssini |  |-  A C_ ( ( C vH A ) i^i ( D vH A ) ) | 
						
							| 16 | 15 | a1i |  |-  ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) -> A C_ ( ( C vH A ) i^i ( D vH A ) ) ) | 
						
							| 17 | 3 2 1 | chlej1i |  |-  ( C C_ B -> ( C vH A ) C_ ( B vH A ) ) | 
						
							| 18 | 2 1 | chjcomi |  |-  ( B vH A ) = ( A vH B ) | 
						
							| 19 | 17 18 | sseqtrdi |  |-  ( C C_ B -> ( C vH A ) C_ ( A vH B ) ) | 
						
							| 20 |  | ssinss1 |  |-  ( ( C vH A ) C_ ( A vH B ) -> ( ( C vH A ) i^i ( D vH A ) ) C_ ( A vH B ) ) | 
						
							| 21 | 19 20 | syl |  |-  ( C C_ B -> ( ( C vH A ) i^i ( D vH A ) ) C_ ( A vH B ) ) | 
						
							| 22 | 21 | adantr |  |-  ( ( C C_ B /\ D C_ B ) -> ( ( C vH A ) i^i ( D vH A ) ) C_ ( A vH B ) ) | 
						
							| 23 | 3 1 | chjcli |  |-  ( C vH A ) e. CH | 
						
							| 24 | 4 1 | chjcli |  |-  ( D vH A ) e. CH | 
						
							| 25 | 23 24 | chincli |  |-  ( ( C vH A ) i^i ( D vH A ) ) e. CH | 
						
							| 26 | 1 2 25 | 3pm3.2i |  |-  ( A e. CH /\ B e. CH /\ ( ( C vH A ) i^i ( D vH A ) ) e. CH ) | 
						
							| 27 |  | dmdsl3 |  |-  ( ( ( A e. CH /\ B e. CH /\ ( ( C vH A ) i^i ( D vH A ) ) e. CH ) /\ ( B MH* A /\ A C_ ( ( C vH A ) i^i ( D vH A ) ) /\ ( ( C vH A ) i^i ( D vH A ) ) C_ ( A vH B ) ) ) -> ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) vH A ) = ( ( C vH A ) i^i ( D vH A ) ) ) | 
						
							| 28 | 26 27 | mpan |  |-  ( ( B MH* A /\ A C_ ( ( C vH A ) i^i ( D vH A ) ) /\ ( ( C vH A ) i^i ( D vH A ) ) C_ ( A vH B ) ) -> ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) vH A ) = ( ( C vH A ) i^i ( D vH A ) ) ) | 
						
							| 29 | 12 16 22 28 | syl3an |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) vH A ) = ( ( C vH A ) i^i ( D vH A ) ) ) | 
						
							| 30 |  | inss1 |  |-  ( ( C vH A ) i^i ( D vH A ) ) C_ ( C vH A ) | 
						
							| 31 |  | ssrin |  |-  ( ( ( C vH A ) i^i ( D vH A ) ) C_ ( C vH A ) -> ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( ( C vH A ) i^i B ) ) | 
						
							| 32 | 30 31 | ax-mp |  |-  ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( ( C vH A ) i^i B ) | 
						
							| 33 |  | simpl |  |-  ( ( A MH B /\ B MH* A ) -> A MH B ) | 
						
							| 34 |  | simpl |  |-  ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) -> ( A i^i B ) C_ C ) | 
						
							| 35 |  | simpl |  |-  ( ( C C_ B /\ D C_ B ) -> C C_ B ) | 
						
							| 36 | 1 2 3 | 3pm3.2i |  |-  ( A e. CH /\ B e. CH /\ C e. CH ) | 
						
							| 37 |  | 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 ) | 
						
							| 38 | 36 37 | mpan |  |-  ( ( A MH B /\ ( A i^i B ) C_ C /\ C C_ B ) -> ( ( C vH A ) i^i B ) = C ) | 
						
							| 39 | 33 34 35 38 | syl3an |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( C vH A ) i^i B ) = C ) | 
						
							| 40 | 32 39 | sseqtrid |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ C ) | 
						
							| 41 |  | inss2 |  |-  ( ( C vH A ) i^i ( D vH A ) ) C_ ( D vH A ) | 
						
							| 42 |  | ssrin |  |-  ( ( ( C vH A ) i^i ( D vH A ) ) C_ ( D vH A ) -> ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( ( D vH A ) i^i B ) ) | 
						
							| 43 | 41 42 | ax-mp |  |-  ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( ( D vH A ) i^i B ) | 
						
							| 44 |  | simpr |  |-  ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) -> ( A i^i B ) C_ D ) | 
						
							| 45 |  | simpr |  |-  ( ( C C_ B /\ D C_ B ) -> D C_ B ) | 
						
							| 46 | 1 2 4 | 3pm3.2i |  |-  ( A e. CH /\ B e. CH /\ D e. CH ) | 
						
							| 47 |  | 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 ) | 
						
							| 48 | 46 47 | mpan |  |-  ( ( A MH B /\ ( A i^i B ) C_ D /\ D C_ B ) -> ( ( D vH A ) i^i B ) = D ) | 
						
							| 49 | 33 44 45 48 | syl3an |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( D vH A ) i^i B ) = D ) | 
						
							| 50 | 43 49 | sseqtrid |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ D ) | 
						
							| 51 | 40 50 | ssind |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( C i^i D ) ) | 
						
							| 52 | 25 2 | chincli |  |-  ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) e. CH | 
						
							| 53 | 3 4 | chincli |  |-  ( C i^i D ) e. CH | 
						
							| 54 | 52 53 1 | chlej1i |  |-  ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) C_ ( C i^i D ) -> ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) vH A ) C_ ( ( C i^i D ) vH A ) ) | 
						
							| 55 | 51 54 | syl |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( ( ( C vH A ) i^i ( D vH A ) ) i^i B ) vH A ) C_ ( ( C i^i D ) vH A ) ) | 
						
							| 56 | 29 55 | eqsstrrd |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) -> ( ( C vH A ) i^i ( D vH A ) ) C_ ( ( C i^i D ) vH A ) ) | 
						
							| 57 | 56 | 3expb |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( ( A i^i B ) C_ C /\ ( A i^i B ) C_ D ) /\ ( C C_ B /\ D C_ B ) ) ) -> ( ( C vH A ) i^i ( D vH A ) ) C_ ( ( C i^i D ) vH A ) ) | 
						
							| 58 | 11 57 | sylan2b |  |-  ( ( ( 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 ( D vH A ) ) C_ ( ( C i^i D ) vH A ) ) | 
						
							| 59 | 6 58 | eqssd |  |-  ( ( ( A MH B /\ B MH* A ) /\ ( ( A i^i B ) C_ ( C i^i D ) /\ ( C vH D ) C_ B ) ) -> ( ( C i^i D ) vH A ) = ( ( C vH A ) i^i ( D vH A ) ) ) |