| Step | Hyp | Ref | Expression | 
						
							| 1 |  | omxpenlem.1 | ⊢ 𝐹  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐴  ↦  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) | 
						
							| 2 |  | eloni | ⊢ ( 𝐵  ∈  On  →  Ord  𝐵 ) | 
						
							| 3 | 2 | ad2antlr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  Ord  𝐵 ) | 
						
							| 4 |  | simprl | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝑥  ∈  𝐵 ) | 
						
							| 5 |  | ordsucss | ⊢ ( Ord  𝐵  →  ( 𝑥  ∈  𝐵  →  suc  𝑥  ⊆  𝐵 ) ) | 
						
							| 6 | 3 4 5 | sylc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  suc  𝑥  ⊆  𝐵 ) | 
						
							| 7 |  | onelon | ⊢ ( ( 𝐵  ∈  On  ∧  𝑥  ∈  𝐵 )  →  𝑥  ∈  On ) | 
						
							| 8 | 7 | ad2ant2lr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝑥  ∈  On ) | 
						
							| 9 |  | onsuc | ⊢ ( 𝑥  ∈  On  →  suc  𝑥  ∈  On ) | 
						
							| 10 | 8 9 | syl | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  suc  𝑥  ∈  On ) | 
						
							| 11 |  | simplr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝐵  ∈  On ) | 
						
							| 12 |  | simpll | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝐴  ∈  On ) | 
						
							| 13 |  | omwordi | ⊢ ( ( suc  𝑥  ∈  On  ∧  𝐵  ∈  On  ∧  𝐴  ∈  On )  →  ( suc  𝑥  ⊆  𝐵  →  ( 𝐴  ·o  suc  𝑥 )  ⊆  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 14 | 10 11 12 13 | syl3anc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( suc  𝑥  ⊆  𝐵  →  ( 𝐴  ·o  suc  𝑥 )  ⊆  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 15 | 6 14 | mpd | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝐴  ·o  suc  𝑥 )  ⊆  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 16 |  | simprr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝑦  ∈  𝐴 ) | 
						
							| 17 |  | onelon | ⊢ ( ( 𝐴  ∈  On  ∧  𝑦  ∈  𝐴 )  →  𝑦  ∈  On ) | 
						
							| 18 | 17 | ad2ant2rl | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  𝑦  ∈  On ) | 
						
							| 19 |  | omcl | ⊢ ( ( 𝐴  ∈  On  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝑥 )  ∈  On ) | 
						
							| 20 | 12 8 19 | syl2anc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝐴  ·o  𝑥 )  ∈  On ) | 
						
							| 21 |  | oaord | ⊢ ( ( 𝑦  ∈  On  ∧  𝐴  ∈  On  ∧  ( 𝐴  ·o  𝑥 )  ∈  On )  →  ( 𝑦  ∈  𝐴  ↔  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( ( 𝐴  ·o  𝑥 )  +o  𝐴 ) ) ) | 
						
							| 22 | 18 12 20 21 | syl3anc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝑦  ∈  𝐴  ↔  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( ( 𝐴  ·o  𝑥 )  +o  𝐴 ) ) ) | 
						
							| 23 | 16 22 | mpbid | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( ( 𝐴  ·o  𝑥 )  +o  𝐴 ) ) | 
						
							| 24 |  | omsuc | ⊢ ( ( 𝐴  ∈  On  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  suc  𝑥 )  =  ( ( 𝐴  ·o  𝑥 )  +o  𝐴 ) ) | 
						
							| 25 | 12 8 24 | syl2anc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝐴  ·o  suc  𝑥 )  =  ( ( 𝐴  ·o  𝑥 )  +o  𝐴 ) ) | 
						
							| 26 | 23 25 | eleqtrrd | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  suc  𝑥 ) ) | 
						
							| 27 | 15 26 | sseldd | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 ) )  →  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 28 | 27 | ralrimivva | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐴 ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 29 | 1 | fmpo | ⊢ ( ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐴 ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ↔  𝐹 : ( 𝐵  ×  𝐴 ) ⟶ ( 𝐴  ·o  𝐵 ) ) | 
						
							| 30 | 28 29 | sylib | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  𝐹 : ( 𝐵  ×  𝐴 ) ⟶ ( 𝐴  ·o  𝐵 ) ) | 
						
							| 31 | 30 | ffnd | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  𝐹  Fn  ( 𝐵  ×  𝐴 ) ) | 
						
							| 32 |  | simpll | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  𝐴  ∈  On ) | 
						
							| 33 |  | omcl | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( 𝐴  ·o  𝐵 )  ∈  On ) | 
						
							| 34 |  | onelon | ⊢ ( ( ( 𝐴  ·o  𝐵 )  ∈  On  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  𝑚  ∈  On ) | 
						
							| 35 | 33 34 | sylan | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  𝑚  ∈  On ) | 
						
							| 36 |  | noel | ⊢ ¬  𝑚  ∈  ∅ | 
						
							| 37 |  | oveq1 | ⊢ ( 𝐴  =  ∅  →  ( 𝐴  ·o  𝐵 )  =  ( ∅  ·o  𝐵 ) ) | 
						
							| 38 |  | om0r | ⊢ ( 𝐵  ∈  On  →  ( ∅  ·o  𝐵 )  =  ∅ ) | 
						
							| 39 | 37 38 | sylan9eqr | ⊢ ( ( 𝐵  ∈  On  ∧  𝐴  =  ∅ )  →  ( 𝐴  ·o  𝐵 )  =  ∅ ) | 
						
							| 40 | 39 | eleq2d | ⊢ ( ( 𝐵  ∈  On  ∧  𝐴  =  ∅ )  →  ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  ↔  𝑚  ∈  ∅ ) ) | 
						
							| 41 | 36 40 | mtbiri | ⊢ ( ( 𝐵  ∈  On  ∧  𝐴  =  ∅ )  →  ¬  𝑚  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 42 | 41 | ex | ⊢ ( 𝐵  ∈  On  →  ( 𝐴  =  ∅  →  ¬  𝑚  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 43 | 42 | necon2ad | ⊢ ( 𝐵  ∈  On  →  ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  →  𝐴  ≠  ∅ ) ) | 
						
							| 44 | 43 | adantl | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  →  𝐴  ≠  ∅ ) ) | 
						
							| 45 | 44 | imp | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  𝐴  ≠  ∅ ) | 
						
							| 46 |  | omeu | ⊢ ( ( 𝐴  ∈  On  ∧  𝑚  ∈  On  ∧  𝐴  ≠  ∅ )  →  ∃! 𝑛 ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) | 
						
							| 47 | 32 35 45 46 | syl3anc | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ∃! 𝑛 ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) | 
						
							| 48 |  | vex | ⊢ 𝑚  ∈  V | 
						
							| 49 |  | vex | ⊢ 𝑛  ∈  V | 
						
							| 50 | 48 49 | brcnv | ⊢ ( 𝑚 ◡ 𝐹 𝑛  ↔  𝑛 𝐹 𝑚 ) | 
						
							| 51 |  | eleq1 | ⊢ ( 𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  →  ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  ↔  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 52 | 51 | biimpac | ⊢ ( ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) )  →  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 53 | 7 | ex | ⊢ ( 𝐵  ∈  On  →  ( 𝑥  ∈  𝐵  →  𝑥  ∈  On ) ) | 
						
							| 54 | 53 | ad2antlr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐵  →  𝑥  ∈  On ) ) | 
						
							| 55 |  | simplll | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝐴  ∈  On ) | 
						
							| 56 |  | simpr | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝑥  ∈  On ) | 
						
							| 57 | 55 56 19 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝑥 )  ∈  On ) | 
						
							| 58 |  | simplrr | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝑦  ∈  𝐴 ) | 
						
							| 59 | 55 58 17 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝑦  ∈  On ) | 
						
							| 60 |  | oaword1 | ⊢ ( ( ( 𝐴  ·o  𝑥 )  ∈  On  ∧  𝑦  ∈  On )  →  ( 𝐴  ·o  𝑥 )  ⊆  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) | 
						
							| 61 | 57 59 60 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝑥 )  ⊆  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) | 
						
							| 62 |  | simplrl | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 63 | 33 | ad2antrr | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝐵 )  ∈  On ) | 
						
							| 64 |  | ontr2 | ⊢ ( ( ( 𝐴  ·o  𝑥 )  ∈  On  ∧  ( 𝐴  ·o  𝐵 )  ∈  On )  →  ( ( ( 𝐴  ·o  𝑥 )  ⊆  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝐴  ·o  𝑥 )  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 65 | 57 63 64 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( ( ( 𝐴  ·o  𝑥 )  ⊆  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝐴  ·o  𝑥 )  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 66 | 61 62 65 | mp2and | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝑥 )  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 67 |  | simpllr | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝐵  ∈  On ) | 
						
							| 68 | 62 | ne0d | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝐴  ·o  𝐵 )  ≠  ∅ ) | 
						
							| 69 |  | on0eln0 | ⊢ ( ( 𝐴  ·o  𝐵 )  ∈  On  →  ( ∅  ∈  ( 𝐴  ·o  𝐵 )  ↔  ( 𝐴  ·o  𝐵 )  ≠  ∅ ) ) | 
						
							| 70 | 63 69 | syl | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( ∅  ∈  ( 𝐴  ·o  𝐵 )  ↔  ( 𝐴  ·o  𝐵 )  ≠  ∅ ) ) | 
						
							| 71 | 68 70 | mpbird | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ∅  ∈  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 72 |  | om00el | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( ∅  ∈  ( 𝐴  ·o  𝐵 )  ↔  ( ∅  ∈  𝐴  ∧  ∅  ∈  𝐵 ) ) ) | 
						
							| 73 | 72 | ad2antrr | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( ∅  ∈  ( 𝐴  ·o  𝐵 )  ↔  ( ∅  ∈  𝐴  ∧  ∅  ∈  𝐵 ) ) ) | 
						
							| 74 | 71 73 | mpbid | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( ∅  ∈  𝐴  ∧  ∅  ∈  𝐵 ) ) | 
						
							| 75 | 74 | simpld | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ∅  ∈  𝐴 ) | 
						
							| 76 |  | omord2 | ⊢ ( ( ( 𝑥  ∈  On  ∧  𝐵  ∈  On  ∧  𝐴  ∈  On )  ∧  ∅  ∈  𝐴 )  →  ( 𝑥  ∈  𝐵  ↔  ( 𝐴  ·o  𝑥 )  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 77 | 56 67 55 75 76 | syl31anc | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  ( 𝑥  ∈  𝐵  ↔  ( 𝐴  ·o  𝑥 )  ∈  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 78 | 66 77 | mpbird | ⊢ ( ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  ∧  𝑥  ∈  On )  →  𝑥  ∈  𝐵 ) | 
						
							| 79 | 78 | ex | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝑥  ∈  On  →  𝑥  ∈  𝐵 ) ) | 
						
							| 80 | 54 79 | impbid | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑦  ∈  𝐴 ) )  →  ( 𝑥  ∈  𝐵  ↔  𝑥  ∈  On ) ) | 
						
							| 81 | 80 | expr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝑦  ∈  𝐴  →  ( 𝑥  ∈  𝐵  ↔  𝑥  ∈  On ) ) ) | 
						
							| 82 | 81 | pm5.32rd | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ↔  ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 ) ) ) | 
						
							| 83 | 52 82 | sylan2 | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  ( 𝑚  ∈  ( 𝐴  ·o  𝐵 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) )  →  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ↔  ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 ) ) ) | 
						
							| 84 | 83 | expr | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  →  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ↔  ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 ) ) ) ) | 
						
							| 85 | 84 | pm5.32rd | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) )  ↔  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) ) | 
						
							| 86 |  | eqcom | ⊢ ( 𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  ↔  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) | 
						
							| 87 | 86 | anbi2i | ⊢ ( ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) )  ↔  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) | 
						
							| 88 | 85 87 | bitrdi | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) )  ↔  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 89 | 88 | anbi2d | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) )  ↔  ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) ) | 
						
							| 90 |  | an12 | ⊢ ( ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) )  ↔  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 91 | 89 90 | bitrdi | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) )  ↔  ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) ) | 
						
							| 92 | 91 | 2exbidv | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) )  ↔  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) ) | 
						
							| 93 |  | df-mpo | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐴  ↦  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) )  =  { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑚 〉  ∣  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) } | 
						
							| 94 |  | dfoprab2 | ⊢ { 〈 〈 𝑥 ,  𝑦 〉 ,  𝑚 〉  ∣  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) }  =  { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) } | 
						
							| 95 | 1 93 94 | 3eqtri | ⊢ 𝐹  =  { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) } | 
						
							| 96 | 95 | breqi | ⊢ ( 𝑛 𝐹 𝑚  ↔  𝑛 { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) } 𝑚 ) | 
						
							| 97 |  | df-br | ⊢ ( 𝑛 { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) } 𝑚  ↔  〈 𝑛 ,  𝑚 〉  ∈  { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) } ) | 
						
							| 98 |  | opabidw | ⊢ ( 〈 𝑛 ,  𝑚 〉  ∈  { 〈 𝑛 ,  𝑚 〉  ∣  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) }  ↔  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) ) | 
						
							| 99 | 96 97 98 | 3bitri | ⊢ ( 𝑛 𝐹 𝑚  ↔  ∃ 𝑥 ∃ 𝑦 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐴 )  ∧  𝑚  =  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 ) ) ) ) | 
						
							| 100 |  | r2ex | ⊢ ( ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 )  ↔  ∃ 𝑥 ∃ 𝑦 ( ( 𝑥  ∈  On  ∧  𝑦  ∈  𝐴 )  ∧  ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 101 | 92 99 100 | 3bitr4g | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝑛 𝐹 𝑚  ↔  ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 102 | 50 101 | bitrid | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( 𝑚 ◡ 𝐹 𝑛  ↔  ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 103 | 102 | eubidv | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ( ∃! 𝑛 𝑚 ◡ 𝐹 𝑛  ↔  ∃! 𝑛 ∃ 𝑥  ∈  On ∃ 𝑦  ∈  𝐴 ( 𝑛  =  〈 𝑥 ,  𝑦 〉  ∧  ( ( 𝐴  ·o  𝑥 )  +o  𝑦 )  =  𝑚 ) ) ) | 
						
							| 104 | 47 103 | mpbird | ⊢ ( ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  ∧  𝑚  ∈  ( 𝐴  ·o  𝐵 ) )  →  ∃! 𝑛 𝑚 ◡ 𝐹 𝑛 ) | 
						
							| 105 | 104 | ralrimiva | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ∀ 𝑚  ∈  ( 𝐴  ·o  𝐵 ) ∃! 𝑛 𝑚 ◡ 𝐹 𝑛 ) | 
						
							| 106 |  | fnres | ⊢ ( ( ◡ 𝐹  ↾  ( 𝐴  ·o  𝐵 ) )  Fn  ( 𝐴  ·o  𝐵 )  ↔  ∀ 𝑚  ∈  ( 𝐴  ·o  𝐵 ) ∃! 𝑛 𝑚 ◡ 𝐹 𝑛 ) | 
						
							| 107 | 105 106 | sylibr | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( ◡ 𝐹  ↾  ( 𝐴  ·o  𝐵 ) )  Fn  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 108 |  | relcnv | ⊢ Rel  ◡ 𝐹 | 
						
							| 109 |  | df-rn | ⊢ ran  𝐹  =  dom  ◡ 𝐹 | 
						
							| 110 | 30 | frnd | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ran  𝐹  ⊆  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 111 | 109 110 | eqsstrrid | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  dom  ◡ 𝐹  ⊆  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 112 |  | relssres | ⊢ ( ( Rel  ◡ 𝐹  ∧  dom  ◡ 𝐹  ⊆  ( 𝐴  ·o  𝐵 ) )  →  ( ◡ 𝐹  ↾  ( 𝐴  ·o  𝐵 ) )  =  ◡ 𝐹 ) | 
						
							| 113 | 108 111 112 | sylancr | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( ◡ 𝐹  ↾  ( 𝐴  ·o  𝐵 ) )  =  ◡ 𝐹 ) | 
						
							| 114 | 113 | fneq1d | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( ( ◡ 𝐹  ↾  ( 𝐴  ·o  𝐵 ) )  Fn  ( 𝐴  ·o  𝐵 )  ↔  ◡ 𝐹  Fn  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 115 | 107 114 | mpbid | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ◡ 𝐹  Fn  ( 𝐴  ·o  𝐵 ) ) | 
						
							| 116 |  | dff1o4 | ⊢ ( 𝐹 : ( 𝐵  ×  𝐴 ) –1-1-onto→ ( 𝐴  ·o  𝐵 )  ↔  ( 𝐹  Fn  ( 𝐵  ×  𝐴 )  ∧  ◡ 𝐹  Fn  ( 𝐴  ·o  𝐵 ) ) ) | 
						
							| 117 | 31 115 116 | sylanbrc | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  𝐹 : ( 𝐵  ×  𝐴 ) –1-1-onto→ ( 𝐴  ·o  𝐵 ) ) |