| 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 ) ) )  |