| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oeoalem.1 | ⊢ 𝐴  ∈  On | 
						
							| 2 |  | oeoalem.2 | ⊢ ∅  ∈  𝐴 | 
						
							| 3 |  | oeoalem.3 | ⊢ 𝐵  ∈  On | 
						
							| 4 |  | oveq2 | ⊢ ( 𝑥  =  ∅  →  ( 𝐵  +o  𝑥 )  =  ( 𝐵  +o  ∅ ) ) | 
						
							| 5 | 4 | oveq2d | ⊢ ( 𝑥  =  ∅  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( 𝐴  ↑o  ( 𝐵  +o  ∅ ) ) ) | 
						
							| 6 |  | oveq2 | ⊢ ( 𝑥  =  ∅  →  ( 𝐴  ↑o  𝑥 )  =  ( 𝐴  ↑o  ∅ ) ) | 
						
							| 7 | 6 | oveq2d | ⊢ ( 𝑥  =  ∅  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  ∅ ) ) ) | 
						
							| 8 | 5 7 | eqeq12d | ⊢ ( 𝑥  =  ∅  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  ↔  ( 𝐴  ↑o  ( 𝐵  +o  ∅ ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  ∅ ) ) ) ) | 
						
							| 9 |  | oveq2 | ⊢ ( 𝑥  =  𝑦  →  ( 𝐵  +o  𝑥 )  =  ( 𝐵  +o  𝑦 ) ) | 
						
							| 10 | 9 | oveq2d | ⊢ ( 𝑥  =  𝑦  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 11 |  | oveq2 | ⊢ ( 𝑥  =  𝑦  →  ( 𝐴  ↑o  𝑥 )  =  ( 𝐴  ↑o  𝑦 ) ) | 
						
							| 12 | 11 | oveq2d | ⊢ ( 𝑥  =  𝑦  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 13 | 10 12 | eqeq12d | ⊢ ( 𝑥  =  𝑦  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  ↔  ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) ) | 
						
							| 14 |  | oveq2 | ⊢ ( 𝑥  =  suc  𝑦  →  ( 𝐵  +o  𝑥 )  =  ( 𝐵  +o  suc  𝑦 ) ) | 
						
							| 15 | 14 | oveq2d | ⊢ ( 𝑥  =  suc  𝑦  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) ) ) | 
						
							| 16 |  | oveq2 | ⊢ ( 𝑥  =  suc  𝑦  →  ( 𝐴  ↑o  𝑥 )  =  ( 𝐴  ↑o  suc  𝑦 ) ) | 
						
							| 17 | 16 | oveq2d | ⊢ ( 𝑥  =  suc  𝑦  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) | 
						
							| 18 | 15 17 | eqeq12d | ⊢ ( 𝑥  =  suc  𝑦  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  ↔  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) ) | 
						
							| 19 |  | oveq2 | ⊢ ( 𝑥  =  𝐶  →  ( 𝐵  +o  𝑥 )  =  ( 𝐵  +o  𝐶 ) ) | 
						
							| 20 | 19 | oveq2d | ⊢ ( 𝑥  =  𝐶  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( 𝐴  ↑o  ( 𝐵  +o  𝐶 ) ) ) | 
						
							| 21 |  | oveq2 | ⊢ ( 𝑥  =  𝐶  →  ( 𝐴  ↑o  𝑥 )  =  ( 𝐴  ↑o  𝐶 ) ) | 
						
							| 22 | 21 | oveq2d | ⊢ ( 𝑥  =  𝐶  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝐶 ) ) ) | 
						
							| 23 | 20 22 | eqeq12d | ⊢ ( 𝑥  =  𝐶  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  ↔  ( 𝐴  ↑o  ( 𝐵  +o  𝐶 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝐶 ) ) ) ) | 
						
							| 24 |  | oecl | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( 𝐴  ↑o  𝐵 )  ∈  On ) | 
						
							| 25 | 1 3 24 | mp2an | ⊢ ( 𝐴  ↑o  𝐵 )  ∈  On | 
						
							| 26 |  | om1 | ⊢ ( ( 𝐴  ↑o  𝐵 )  ∈  On  →  ( ( 𝐴  ↑o  𝐵 )  ·o  1o )  =  ( 𝐴  ↑o  𝐵 ) ) | 
						
							| 27 | 25 26 | ax-mp | ⊢ ( ( 𝐴  ↑o  𝐵 )  ·o  1o )  =  ( 𝐴  ↑o  𝐵 ) | 
						
							| 28 |  | oe0 | ⊢ ( 𝐴  ∈  On  →  ( 𝐴  ↑o  ∅ )  =  1o ) | 
						
							| 29 | 1 28 | ax-mp | ⊢ ( 𝐴  ↑o  ∅ )  =  1o | 
						
							| 30 | 29 | oveq2i | ⊢ ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  ∅ ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  1o ) | 
						
							| 31 |  | oa0 | ⊢ ( 𝐵  ∈  On  →  ( 𝐵  +o  ∅ )  =  𝐵 ) | 
						
							| 32 | 3 31 | ax-mp | ⊢ ( 𝐵  +o  ∅ )  =  𝐵 | 
						
							| 33 | 32 | oveq2i | ⊢ ( 𝐴  ↑o  ( 𝐵  +o  ∅ ) )  =  ( 𝐴  ↑o  𝐵 ) | 
						
							| 34 | 27 30 33 | 3eqtr4ri | ⊢ ( 𝐴  ↑o  ( 𝐵  +o  ∅ ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  ∅ ) ) | 
						
							| 35 |  | oasuc | ⊢ ( ( 𝐵  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐵  +o  suc  𝑦 )  =  suc  ( 𝐵  +o  𝑦 ) ) | 
						
							| 36 | 35 | oveq2d | ⊢ ( ( 𝐵  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( 𝐴  ↑o  suc  ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 37 |  | oacl | ⊢ ( ( 𝐵  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐵  +o  𝑦 )  ∈  On ) | 
						
							| 38 |  | oesuc | ⊢ ( ( 𝐴  ∈  On  ∧  ( 𝐵  +o  𝑦 )  ∈  On )  →  ( 𝐴  ↑o  suc  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 39 | 1 37 38 | sylancr | ⊢ ( ( 𝐵  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ↑o  suc  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 40 | 36 39 | eqtrd | ⊢ ( ( 𝐵  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 41 | 3 40 | mpan | ⊢ ( 𝑦  ∈  On  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 42 |  | oveq1 | ⊢ ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  ·o  𝐴 )  =  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 43 | 41 42 | sylan9eq | ⊢ ( ( 𝑦  ∈  On  ∧  ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 ) ) | 
						
							| 44 |  | oecl | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ↑o  𝑦 )  ∈  On ) | 
						
							| 45 |  | omass | ⊢ ( ( ( 𝐴  ↑o  𝐵 )  ∈  On  ∧  ( 𝐴  ↑o  𝑦 )  ∈  On  ∧  𝐴  ∈  On )  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( ( 𝐴  ↑o  𝑦 )  ·o  𝐴 ) ) ) | 
						
							| 46 | 25 1 45 | mp3an13 | ⊢ ( ( 𝐴  ↑o  𝑦 )  ∈  On  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( ( 𝐴  ↑o  𝑦 )  ·o  𝐴 ) ) ) | 
						
							| 47 | 44 46 | syl | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  On )  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( ( 𝐴  ↑o  𝑦 )  ·o  𝐴 ) ) ) | 
						
							| 48 |  | oesuc | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ↑o  suc  𝑦 )  =  ( ( 𝐴  ↑o  𝑦 )  ·o  𝐴 ) ) | 
						
							| 49 | 48 | oveq2d | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  On )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( ( 𝐴  ↑o  𝑦 )  ·o  𝐴 ) ) ) | 
						
							| 50 | 47 49 | eqtr4d | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  On )  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) | 
						
							| 51 | 1 50 | mpan | ⊢ ( 𝑦  ∈  On  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) | 
						
							| 52 | 51 | adantr | ⊢ ( ( 𝑦  ∈  On  ∧  ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  ·o  𝐴 )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) | 
						
							| 53 | 43 52 | eqtrd | ⊢ ( ( 𝑦  ∈  On  ∧  ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) | 
						
							| 54 | 53 | ex | ⊢ ( 𝑦  ∈  On  →  ( ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  suc  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  suc  𝑦 ) ) ) ) | 
						
							| 55 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 56 |  | oalim | ⊢ ( ( 𝐵  ∈  On  ∧  ( 𝑥  ∈  V  ∧  Lim  𝑥 ) )  →  ( 𝐵  +o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) ) | 
						
							| 57 | 3 56 | mpan | ⊢ ( ( 𝑥  ∈  V  ∧  Lim  𝑥 )  →  ( 𝐵  +o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) ) | 
						
							| 58 | 55 57 | mpan | ⊢ ( Lim  𝑥  →  ( 𝐵  +o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) ) | 
						
							| 59 | 58 | oveq2d | ⊢ ( Lim  𝑥  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( 𝐴  ↑o  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 60 |  | limord | ⊢ ( Lim  𝑥  →  Ord  𝑥 ) | 
						
							| 61 |  | ordelon | ⊢ ( ( Ord  𝑥  ∧  𝑦  ∈  𝑥 )  →  𝑦  ∈  On ) | 
						
							| 62 | 60 61 | sylan | ⊢ ( ( Lim  𝑥  ∧  𝑦  ∈  𝑥 )  →  𝑦  ∈  On ) | 
						
							| 63 | 3 62 37 | sylancr | ⊢ ( ( Lim  𝑥  ∧  𝑦  ∈  𝑥 )  →  ( 𝐵  +o  𝑦 )  ∈  On ) | 
						
							| 64 | 63 | ralrimiva | ⊢ ( Lim  𝑥  →  ∀ 𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 )  ∈  On ) | 
						
							| 65 |  | 0ellim | ⊢ ( Lim  𝑥  →  ∅  ∈  𝑥 ) | 
						
							| 66 | 65 | ne0d | ⊢ ( Lim  𝑥  →  𝑥  ≠  ∅ ) | 
						
							| 67 |  | vex | ⊢ 𝑤  ∈  V | 
						
							| 68 |  | oelim | ⊢ ( ( ( 𝐴  ∈  On  ∧  ( 𝑤  ∈  V  ∧  Lim  𝑤 ) )  ∧  ∅  ∈  𝐴 )  →  ( 𝐴  ↑o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( 𝐴  ↑o  𝑧 ) ) | 
						
							| 69 | 2 68 | mpan2 | ⊢ ( ( 𝐴  ∈  On  ∧  ( 𝑤  ∈  V  ∧  Lim  𝑤 ) )  →  ( 𝐴  ↑o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( 𝐴  ↑o  𝑧 ) ) | 
						
							| 70 | 1 69 | mpan | ⊢ ( ( 𝑤  ∈  V  ∧  Lim  𝑤 )  →  ( 𝐴  ↑o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( 𝐴  ↑o  𝑧 ) ) | 
						
							| 71 | 67 70 | mpan | ⊢ ( Lim  𝑤  →  ( 𝐴  ↑o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( 𝐴  ↑o  𝑧 ) ) | 
						
							| 72 |  | oewordi | ⊢ ( ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On  ∧  𝐴  ∈  On )  ∧  ∅  ∈  𝐴 )  →  ( 𝑧  ⊆  𝑤  →  ( 𝐴  ↑o  𝑧 )  ⊆  ( 𝐴  ↑o  𝑤 ) ) ) | 
						
							| 73 | 2 72 | mpan2 | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On  ∧  𝐴  ∈  On )  →  ( 𝑧  ⊆  𝑤  →  ( 𝐴  ↑o  𝑧 )  ⊆  ( 𝐴  ↑o  𝑤 ) ) ) | 
						
							| 74 | 1 73 | mp3an3 | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On )  →  ( 𝑧  ⊆  𝑤  →  ( 𝐴  ↑o  𝑧 )  ⊆  ( 𝐴  ↑o  𝑤 ) ) ) | 
						
							| 75 | 74 | 3impia | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On  ∧  𝑧  ⊆  𝑤 )  →  ( 𝐴  ↑o  𝑧 )  ⊆  ( 𝐴  ↑o  𝑤 ) ) | 
						
							| 76 | 71 75 | onoviun | ⊢ ( ( 𝑥  ∈  V  ∧  ∀ 𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 )  ∈  On  ∧  𝑥  ≠  ∅ )  →  ( 𝐴  ↑o  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 77 | 55 64 66 76 | mp3an2i | ⊢ ( Lim  𝑥  →  ( 𝐴  ↑o  ∪  𝑦  ∈  𝑥 ( 𝐵  +o  𝑦 ) )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 78 | 59 77 | eqtrd | ⊢ ( Lim  𝑥  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) ) ) | 
						
							| 79 |  | iuneq2 | ⊢ ( ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  →  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 80 | 78 79 | sylan9eq | ⊢ ( ( Lim  𝑥  ∧  ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 81 |  | oelim | ⊢ ( ( ( 𝐴  ∈  On  ∧  ( 𝑥  ∈  V  ∧  Lim  𝑥 ) )  ∧  ∅  ∈  𝐴 )  →  ( 𝐴  ↑o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) ) | 
						
							| 82 | 2 81 | mpan2 | ⊢ ( ( 𝐴  ∈  On  ∧  ( 𝑥  ∈  V  ∧  Lim  𝑥 ) )  →  ( 𝐴  ↑o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) ) | 
						
							| 83 | 1 82 | mpan | ⊢ ( ( 𝑥  ∈  V  ∧  Lim  𝑥 )  →  ( 𝐴  ↑o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) ) | 
						
							| 84 | 55 83 | mpan | ⊢ ( Lim  𝑥  →  ( 𝐴  ↑o  𝑥 )  =  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) ) | 
						
							| 85 | 84 | oveq2d | ⊢ ( Lim  𝑥  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 86 | 1 62 44 | sylancr | ⊢ ( ( Lim  𝑥  ∧  𝑦  ∈  𝑥 )  →  ( 𝐴  ↑o  𝑦 )  ∈  On ) | 
						
							| 87 | 86 | ralrimiva | ⊢ ( Lim  𝑥  →  ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 )  ∈  On ) | 
						
							| 88 |  | omlim | ⊢ ( ( ( 𝐴  ↑o  𝐵 )  ∈  On  ∧  ( 𝑤  ∈  V  ∧  Lim  𝑤 ) )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 ) ) | 
						
							| 89 | 25 88 | mpan | ⊢ ( ( 𝑤  ∈  V  ∧  Lim  𝑤 )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 ) ) | 
						
							| 90 | 67 89 | mpan | ⊢ ( Lim  𝑤  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 )  =  ∪  𝑧  ∈  𝑤 ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 ) ) | 
						
							| 91 |  | omwordi | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On  ∧  ( 𝐴  ↑o  𝐵 )  ∈  On )  →  ( 𝑧  ⊆  𝑤  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 )  ⊆  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 ) ) ) | 
						
							| 92 | 25 91 | mp3an3 | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On )  →  ( 𝑧  ⊆  𝑤  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 )  ⊆  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 ) ) ) | 
						
							| 93 | 92 | 3impia | ⊢ ( ( 𝑧  ∈  On  ∧  𝑤  ∈  On  ∧  𝑧  ⊆  𝑤 )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑧 )  ⊆  ( ( 𝐴  ↑o  𝐵 )  ·o  𝑤 ) ) | 
						
							| 94 | 90 93 | onoviun | ⊢ ( ( 𝑥  ∈  V  ∧  ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 )  ∈  On  ∧  𝑥  ≠  ∅ )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 95 | 55 87 66 94 | mp3an2i | ⊢ ( Lim  𝑥  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ∪  𝑦  ∈  𝑥 ( 𝐴  ↑o  𝑦 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 96 | 85 95 | eqtrd | ⊢ ( Lim  𝑥  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 97 | 96 | adantr | ⊢ ( ( Lim  𝑥  ∧  ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) )  =  ∪  𝑦  ∈  𝑥 ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) ) | 
						
							| 98 | 80 97 | eqtr4d | ⊢ ( ( Lim  𝑥  ∧  ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) ) ) | 
						
							| 99 | 98 | ex | ⊢ ( Lim  𝑥  →  ( ∀ 𝑦  ∈  𝑥 ( 𝐴  ↑o  ( 𝐵  +o  𝑦 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑦 ) )  →  ( 𝐴  ↑o  ( 𝐵  +o  𝑥 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝑥 ) ) ) ) | 
						
							| 100 | 8 13 18 23 34 54 99 | tfinds | ⊢ ( 𝐶  ∈  On  →  ( 𝐴  ↑o  ( 𝐵  +o  𝐶 ) )  =  ( ( 𝐴  ↑o  𝐵 )  ·o  ( 𝐴  ↑o  𝐶 ) ) ) |