| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 5oalem1.1 |  |-  A e. SH | 
						
							| 2 |  | 5oalem1.2 |  |-  B e. SH | 
						
							| 3 |  | 5oalem1.3 |  |-  C e. SH | 
						
							| 4 |  | 5oalem1.4 |  |-  R e. SH | 
						
							| 5 |  | simplll |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> x e. A ) | 
						
							| 6 | 1 | sheli |  |-  ( x e. A -> x e. ~H ) | 
						
							| 7 | 6 | ad2antrr |  |-  ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) -> x e. ~H ) | 
						
							| 8 | 3 | sheli |  |-  ( z e. C -> z e. ~H ) | 
						
							| 9 | 8 | adantr |  |-  ( ( z e. C /\ ( x -h z ) e. R ) -> z e. ~H ) | 
						
							| 10 |  | hvaddsub12 |  |-  ( ( x e. ~H /\ z e. ~H /\ z e. ~H ) -> ( x +h ( z -h z ) ) = ( z +h ( x -h z ) ) ) | 
						
							| 11 | 10 | 3anidm23 |  |-  ( ( x e. ~H /\ z e. ~H ) -> ( x +h ( z -h z ) ) = ( z +h ( x -h z ) ) ) | 
						
							| 12 |  | hvsubid |  |-  ( z e. ~H -> ( z -h z ) = 0h ) | 
						
							| 13 | 12 | oveq2d |  |-  ( z e. ~H -> ( x +h ( z -h z ) ) = ( x +h 0h ) ) | 
						
							| 14 |  | ax-hvaddid |  |-  ( x e. ~H -> ( x +h 0h ) = x ) | 
						
							| 15 | 13 14 | sylan9eqr |  |-  ( ( x e. ~H /\ z e. ~H ) -> ( x +h ( z -h z ) ) = x ) | 
						
							| 16 | 11 15 | eqtr3d |  |-  ( ( x e. ~H /\ z e. ~H ) -> ( z +h ( x -h z ) ) = x ) | 
						
							| 17 | 7 9 16 | syl2an |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> ( z +h ( x -h z ) ) = x ) | 
						
							| 18 | 3 4 | shsvai |  |-  ( ( z e. C /\ ( x -h z ) e. R ) -> ( z +h ( x -h z ) ) e. ( C +H R ) ) | 
						
							| 19 | 18 | adantl |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> ( z +h ( x -h z ) ) e. ( C +H R ) ) | 
						
							| 20 | 17 19 | eqeltrrd |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> x e. ( C +H R ) ) | 
						
							| 21 | 5 20 | elind |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> x e. ( A i^i ( C +H R ) ) ) | 
						
							| 22 |  | simpllr |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> y e. B ) | 
						
							| 23 | 3 4 | shscli |  |-  ( C +H R ) e. SH | 
						
							| 24 | 1 23 | shincli |  |-  ( A i^i ( C +H R ) ) e. SH | 
						
							| 25 | 24 2 | shsvai |  |-  ( ( x e. ( A i^i ( C +H R ) ) /\ y e. B ) -> ( x +h y ) e. ( ( A i^i ( C +H R ) ) +H B ) ) | 
						
							| 26 | 24 2 | shscomi |  |-  ( ( A i^i ( C +H R ) ) +H B ) = ( B +H ( A i^i ( C +H R ) ) ) | 
						
							| 27 | 25 26 | eleqtrdi |  |-  ( ( x e. ( A i^i ( C +H R ) ) /\ y e. B ) -> ( x +h y ) e. ( B +H ( A i^i ( C +H R ) ) ) ) | 
						
							| 28 | 21 22 27 | syl2anc |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> ( x +h y ) e. ( B +H ( A i^i ( C +H R ) ) ) ) | 
						
							| 29 |  | eleq1 |  |-  ( v = ( x +h y ) -> ( v e. ( B +H ( A i^i ( C +H R ) ) ) <-> ( x +h y ) e. ( B +H ( A i^i ( C +H R ) ) ) ) ) | 
						
							| 30 | 29 | ad2antlr |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> ( v e. ( B +H ( A i^i ( C +H R ) ) ) <-> ( x +h y ) e. ( B +H ( A i^i ( C +H R ) ) ) ) ) | 
						
							| 31 | 28 30 | mpbird |  |-  ( ( ( ( x e. A /\ y e. B ) /\ v = ( x +h y ) ) /\ ( z e. C /\ ( x -h z ) e. R ) ) -> v e. ( B +H ( A i^i ( C +H R ) ) ) ) |