| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tsksdom | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  𝐴  ≺  𝑇 ) | 
						
							| 2 |  | cardidg | ⊢ ( 𝑇  ∈  Tarski  →  ( card ‘ 𝑇 )  ≈  𝑇 ) | 
						
							| 3 | 2 | ensymd | ⊢ ( 𝑇  ∈  Tarski  →  𝑇  ≈  ( card ‘ 𝑇 ) ) | 
						
							| 4 | 3 | adantr | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  𝑇  ≈  ( card ‘ 𝑇 ) ) | 
						
							| 5 |  | sdomentr | ⊢ ( ( 𝐴  ≺  𝑇  ∧  𝑇  ≈  ( card ‘ 𝑇 ) )  →  𝐴  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 6 | 1 4 5 | syl2anc | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  𝐴  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 7 |  | eqid | ⊢ ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  =  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) | 
						
							| 8 | 7 | rnmpt | ⊢ ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  =  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) } | 
						
							| 9 |  | cardon | ⊢ ( card ‘ 𝑇 )  ∈  On | 
						
							| 10 |  | sdomdom | ⊢ ( 𝐴  ≺  ( card ‘ 𝑇 )  →  𝐴  ≼  ( card ‘ 𝑇 ) ) | 
						
							| 11 |  | ondomen | ⊢ ( ( ( card ‘ 𝑇 )  ∈  On  ∧  𝐴  ≼  ( card ‘ 𝑇 ) )  →  𝐴  ∈  dom  card ) | 
						
							| 12 | 9 10 11 | sylancr | ⊢ ( 𝐴  ≺  ( card ‘ 𝑇 )  →  𝐴  ∈  dom  card ) | 
						
							| 13 | 12 | adantl | ⊢ ( ( 𝐴  ∈  𝑇  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  𝐴  ∈  dom  card ) | 
						
							| 14 |  | vex | ⊢ 𝑓  ∈  V | 
						
							| 15 | 14 | imaex | ⊢ ( 𝑓  “  𝑥 )  ∈  V | 
						
							| 16 | 15 7 | fnmpti | ⊢ ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  Fn  𝐴 | 
						
							| 17 |  | dffn4 | ⊢ ( ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  Fn  𝐴  ↔  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) : 𝐴 –onto→ ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) ) | 
						
							| 18 | 16 17 | mpbi | ⊢ ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) : 𝐴 –onto→ ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) | 
						
							| 19 |  | fodomnum | ⊢ ( 𝐴  ∈  dom  card  →  ( ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) ) : 𝐴 –onto→ ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  →  ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  ≼  𝐴 ) ) | 
						
							| 20 | 13 18 19 | mpisyl | ⊢ ( ( 𝐴  ∈  𝑇  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  ran  ( 𝑥  ∈  𝐴  ↦  ( 𝑓  “  𝑥 ) )  ≼  𝐴 ) | 
						
							| 21 | 8 20 | eqbrtrrid | ⊢ ( ( 𝐴  ∈  𝑇  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≼  𝐴 ) | 
						
							| 22 |  | domsdomtr | ⊢ ( ( { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≼  𝐴  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 23 | 21 22 | sylancom | ⊢ ( ( 𝐴  ∈  𝑇  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 24 | 23 | adantll | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  ∧  𝐴  ≺  ( card ‘ 𝑇 ) )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 25 | 6 24 | mpdan | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 26 |  | ne0i | ⊢ ( 𝐴  ∈  𝑇  →  𝑇  ≠  ∅ ) | 
						
							| 27 |  | tskcard | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝑇  ≠  ∅ )  →  ( card ‘ 𝑇 )  ∈  Inacc ) | 
						
							| 28 | 26 27 | sylan2 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  ( card ‘ 𝑇 )  ∈  Inacc ) | 
						
							| 29 |  | elina | ⊢ ( ( card ‘ 𝑇 )  ∈  Inacc  ↔  ( ( card ‘ 𝑇 )  ≠  ∅  ∧  ( cf ‘ ( card ‘ 𝑇 ) )  =  ( card ‘ 𝑇 )  ∧  ∀ 𝑥  ∈  ( card ‘ 𝑇 ) 𝒫  𝑥  ≺  ( card ‘ 𝑇 ) ) ) | 
						
							| 30 | 29 | simp2bi | ⊢ ( ( card ‘ 𝑇 )  ∈  Inacc  →  ( cf ‘ ( card ‘ 𝑇 ) )  =  ( card ‘ 𝑇 ) ) | 
						
							| 31 | 28 30 | syl | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  ( cf ‘ ( card ‘ 𝑇 ) )  =  ( card ‘ 𝑇 ) ) | 
						
							| 32 | 25 31 | breqtrrd | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝐴  ∈  𝑇 )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) | 
						
							| 33 | 32 | 3adant2 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) | 
						
							| 34 | 33 | adantr | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) | 
						
							| 35 | 28 | 3adant2 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ( card ‘ 𝑇 )  ∈  Inacc ) | 
						
							| 36 | 35 | adantr | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ( card ‘ 𝑇 )  ∈  Inacc ) | 
						
							| 37 |  | inawina | ⊢ ( ( card ‘ 𝑇 )  ∈  Inacc  →  ( card ‘ 𝑇 )  ∈  Inaccw ) | 
						
							| 38 |  | winalim | ⊢ ( ( card ‘ 𝑇 )  ∈  Inaccw  →  Lim  ( card ‘ 𝑇 ) ) | 
						
							| 39 | 36 37 38 | 3syl | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  Lim  ( card ‘ 𝑇 ) ) | 
						
							| 40 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 41 |  | eqeq1 | ⊢ ( 𝑧  =  𝑦  →  ( 𝑧  =  ( 𝑓  “  𝑥 )  ↔  𝑦  =  ( 𝑓  “  𝑥 ) ) ) | 
						
							| 42 | 41 | rexbidv | ⊢ ( 𝑧  =  𝑦  →  ( ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 )  ↔  ∃ 𝑥  ∈  𝐴 𝑦  =  ( 𝑓  “  𝑥 ) ) ) | 
						
							| 43 | 40 42 | elab | ⊢ ( 𝑦  ∈  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ↔  ∃ 𝑥  ∈  𝐴 𝑦  =  ( 𝑓  “  𝑥 ) ) | 
						
							| 44 |  | imassrn | ⊢ ( 𝑓  “  𝑥 )  ⊆  ran  𝑓 | 
						
							| 45 |  | f1ofo | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 ) ) | 
						
							| 46 |  | forn | ⊢ ( 𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 )  →  ran  𝑓  =  ( card ‘ 𝑇 ) ) | 
						
							| 47 | 45 46 | syl | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ran  𝑓  =  ( card ‘ 𝑇 ) ) | 
						
							| 48 | 44 47 | sseqtrid | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) | 
						
							| 49 | 48 | ad2antlr | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) | 
						
							| 50 |  | f1of1 | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  𝑓 : ∪  𝐴 –1-1→ ( card ‘ 𝑇 ) ) | 
						
							| 51 |  | elssuni | ⊢ ( 𝑥  ∈  𝐴  →  𝑥  ⊆  ∪  𝐴 ) | 
						
							| 52 |  | vex | ⊢ 𝑥  ∈  V | 
						
							| 53 | 52 | f1imaen | ⊢ ( ( 𝑓 : ∪  𝐴 –1-1→ ( card ‘ 𝑇 )  ∧  𝑥  ⊆  ∪  𝐴 )  →  ( 𝑓  “  𝑥 )  ≈  𝑥 ) | 
						
							| 54 | 50 51 53 | syl2an | ⊢ ( ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑓  “  𝑥 )  ≈  𝑥 ) | 
						
							| 55 | 54 | adantll | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑓  “  𝑥 )  ≈  𝑥 ) | 
						
							| 56 |  | simpl1 | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑥  ∈  𝐴 )  →  𝑇  ∈  Tarski ) | 
						
							| 57 |  | trss | ⊢ ( Tr  𝑇  →  ( 𝐴  ∈  𝑇  →  𝐴  ⊆  𝑇 ) ) | 
						
							| 58 | 57 | imp | ⊢ ( ( Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  𝐴  ⊆  𝑇 ) | 
						
							| 59 | 58 | 3adant1 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  𝐴  ⊆  𝑇 ) | 
						
							| 60 | 59 | sselda | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑥  ∈  𝐴 )  →  𝑥  ∈  𝑇 ) | 
						
							| 61 |  | tsksdom | ⊢ ( ( 𝑇  ∈  Tarski  ∧  𝑥  ∈  𝑇 )  →  𝑥  ≺  𝑇 ) | 
						
							| 62 | 56 60 61 | syl2anc | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑥  ∈  𝐴 )  →  𝑥  ≺  𝑇 ) | 
						
							| 63 | 56 3 | syl | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑥  ∈  𝐴 )  →  𝑇  ≈  ( card ‘ 𝑇 ) ) | 
						
							| 64 |  | sdomentr | ⊢ ( ( 𝑥  ≺  𝑇  ∧  𝑇  ≈  ( card ‘ 𝑇 ) )  →  𝑥  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 65 | 62 63 64 | syl2anc | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑥  ∈  𝐴 )  →  𝑥  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 66 | 65 | adantlr | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  𝑥  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 67 |  | ensdomtr | ⊢ ( ( ( 𝑓  “  𝑥 )  ≈  𝑥  ∧  𝑥  ≺  ( card ‘ 𝑇 ) )  →  ( 𝑓  “  𝑥 )  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 68 | 55 66 67 | syl2anc | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑓  “  𝑥 )  ≺  ( card ‘ 𝑇 ) ) | 
						
							| 69 | 36 30 | syl | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ( cf ‘ ( card ‘ 𝑇 ) )  =  ( card ‘ 𝑇 ) ) | 
						
							| 70 | 69 | adantr | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( cf ‘ ( card ‘ 𝑇 ) )  =  ( card ‘ 𝑇 ) ) | 
						
							| 71 | 68 70 | breqtrrd | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑓  “  𝑥 )  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) | 
						
							| 72 |  | sseq1 | ⊢ ( 𝑦  =  ( 𝑓  “  𝑥 )  →  ( 𝑦  ⊆  ( card ‘ 𝑇 )  ↔  ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) ) | 
						
							| 73 |  | breq1 | ⊢ ( 𝑦  =  ( 𝑓  “  𝑥 )  →  ( 𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) )  ↔  ( 𝑓  “  𝑥 )  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) | 
						
							| 74 | 72 73 | anbi12d | ⊢ ( 𝑦  =  ( 𝑓  “  𝑥 )  →  ( ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) )  ↔  ( ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 )  ∧  ( 𝑓  “  𝑥 )  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) ) | 
						
							| 75 | 74 | biimprcd | ⊢ ( ( ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 )  ∧  ( 𝑓  “  𝑥 )  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) )  →  ( 𝑦  =  ( 𝑓  “  𝑥 )  →  ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) ) | 
						
							| 76 | 49 71 75 | syl2anc | ⊢ ( ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  ∧  𝑥  ∈  𝐴 )  →  ( 𝑦  =  ( 𝑓  “  𝑥 )  →  ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) ) | 
						
							| 77 | 76 | rexlimdva | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ( ∃ 𝑥  ∈  𝐴 𝑦  =  ( 𝑓  “  𝑥 )  →  ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) ) | 
						
							| 78 | 43 77 | biimtrid | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ( 𝑦  ∈  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  →  ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) ) | 
						
							| 79 | 78 | ralrimiv | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ∀ 𝑦  ∈  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) } ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) ) | 
						
							| 80 |  | fvex | ⊢ ( card ‘ 𝑇 )  ∈  V | 
						
							| 81 | 80 | cfslb2n | ⊢ ( ( Lim  ( card ‘ 𝑇 )  ∧  ∀ 𝑦  ∈  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) } ( 𝑦  ⊆  ( card ‘ 𝑇 )  ∧  𝑦  ≺  ( cf ‘ ( card ‘ 𝑇 ) ) ) )  →  ( { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( cf ‘ ( card ‘ 𝑇 ) )  →  ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≠  ( card ‘ 𝑇 ) ) ) | 
						
							| 82 | 39 79 81 | syl2anc | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ( { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≺  ( cf ‘ ( card ‘ 𝑇 ) )  →  ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≠  ( card ‘ 𝑇 ) ) ) | 
						
							| 83 | 34 82 | mpd | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≠  ( card ‘ 𝑇 ) ) | 
						
							| 84 | 15 | dfiun2 | ⊢ ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  =  ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) } | 
						
							| 85 | 48 | ralrimivw | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ∀ 𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) | 
						
							| 86 |  | iunss | ⊢ ( ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 )  ↔  ∀ 𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) | 
						
							| 87 | 85 86 | sylibr | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  ⊆  ( card ‘ 𝑇 ) ) | 
						
							| 88 |  | fof | ⊢ ( 𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 )  →  𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 ) ) | 
						
							| 89 |  | foelrn | ⊢ ( ( 𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 )  ∧  𝑦  ∈  ( card ‘ 𝑇 ) )  →  ∃ 𝑧  ∈  ∪  𝐴 𝑦  =  ( 𝑓 ‘ 𝑧 ) ) | 
						
							| 90 | 89 | ex | ⊢ ( 𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 )  →  ( 𝑦  ∈  ( card ‘ 𝑇 )  →  ∃ 𝑧  ∈  ∪  𝐴 𝑦  =  ( 𝑓 ‘ 𝑧 ) ) ) | 
						
							| 91 |  | eluni2 | ⊢ ( 𝑧  ∈  ∪  𝐴  ↔  ∃ 𝑥  ∈  𝐴 𝑧  ∈  𝑥 ) | 
						
							| 92 |  | nfv | ⊢ Ⅎ 𝑥 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 ) | 
						
							| 93 |  | nfiu1 | ⊢ Ⅎ 𝑥 ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) | 
						
							| 94 | 93 | nfel2 | ⊢ Ⅎ 𝑥 ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) | 
						
							| 95 |  | ssiun2 | ⊢ ( 𝑥  ∈  𝐴  →  ( 𝑓  “  𝑥 )  ⊆  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) | 
						
							| 96 | 95 | 3ad2ant2 | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  ( 𝑓  “  𝑥 )  ⊆  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) | 
						
							| 97 |  | ffn | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  𝑓  Fn  ∪  𝐴 ) | 
						
							| 98 | 97 | 3ad2ant1 | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  𝑓  Fn  ∪  𝐴 ) | 
						
							| 99 | 51 | 3ad2ant2 | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  𝑥  ⊆  ∪  𝐴 ) | 
						
							| 100 |  | simp3 | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  𝑧  ∈  𝑥 ) | 
						
							| 101 |  | fnfvima | ⊢ ( ( 𝑓  Fn  ∪  𝐴  ∧  𝑥  ⊆  ∪  𝐴  ∧  𝑧  ∈  𝑥 )  →  ( 𝑓 ‘ 𝑧 )  ∈  ( 𝑓  “  𝑥 ) ) | 
						
							| 102 | 98 99 100 101 | syl3anc | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  ( 𝑓 ‘ 𝑧 )  ∈  ( 𝑓  “  𝑥 ) ) | 
						
							| 103 | 96 102 | sseldd | ⊢ ( ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  ∧  𝑥  ∈  𝐴  ∧  𝑧  ∈  𝑥 )  →  ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) | 
						
							| 104 | 103 | 3exp | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  ( 𝑥  ∈  𝐴  →  ( 𝑧  ∈  𝑥  →  ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) ) | 
						
							| 105 | 92 94 104 | rexlimd | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  ( ∃ 𝑥  ∈  𝐴 𝑧  ∈  𝑥  →  ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 106 | 91 105 | biimtrid | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  ( 𝑧  ∈  ∪  𝐴  →  ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 107 |  | eleq1a | ⊢ ( ( 𝑓 ‘ 𝑧 )  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  →  ( 𝑦  =  ( 𝑓 ‘ 𝑧 )  →  𝑦  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 108 | 106 107 | syl6 | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  ( 𝑧  ∈  ∪  𝐴  →  ( 𝑦  =  ( 𝑓 ‘ 𝑧 )  →  𝑦  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) ) | 
						
							| 109 | 108 | rexlimdv | ⊢ ( 𝑓 : ∪  𝐴 ⟶ ( card ‘ 𝑇 )  →  ( ∃ 𝑧  ∈  ∪  𝐴 𝑦  =  ( 𝑓 ‘ 𝑧 )  →  𝑦  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 110 | 88 90 109 | sylsyld | ⊢ ( 𝑓 : ∪  𝐴 –onto→ ( card ‘ 𝑇 )  →  ( 𝑦  ∈  ( card ‘ 𝑇 )  →  𝑦  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 111 | 45 110 | syl | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ( 𝑦  ∈  ( card ‘ 𝑇 )  →  𝑦  ∈  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) ) | 
						
							| 112 | 111 | ssrdv | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ( card ‘ 𝑇 )  ⊆  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 ) ) | 
						
							| 113 | 87 112 | eqssd | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ∪  𝑥  ∈  𝐴 ( 𝑓  “  𝑥 )  =  ( card ‘ 𝑇 ) ) | 
						
							| 114 | 84 113 | eqtr3id | ⊢ ( 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 )  →  ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  =  ( card ‘ 𝑇 ) ) | 
						
							| 115 | 114 | necon3ai | ⊢ ( ∪  { 𝑧  ∣  ∃ 𝑥  ∈  𝐴 𝑧  =  ( 𝑓  “  𝑥 ) }  ≠  ( card ‘ 𝑇 )  →  ¬  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 116 | 83 115 | syl | ⊢ ( ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  ∧  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) )  →  ¬  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 117 | 116 | pm2.01da | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ¬  𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 118 | 117 | nexdv | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ¬  ∃ 𝑓 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 119 |  | entr | ⊢ ( ( ∪  𝐴  ≈  𝑇  ∧  𝑇  ≈  ( card ‘ 𝑇 ) )  →  ∪  𝐴  ≈  ( card ‘ 𝑇 ) ) | 
						
							| 120 | 3 119 | sylan2 | ⊢ ( ( ∪  𝐴  ≈  𝑇  ∧  𝑇  ∈  Tarski )  →  ∪  𝐴  ≈  ( card ‘ 𝑇 ) ) | 
						
							| 121 |  | bren | ⊢ ( ∪  𝐴  ≈  ( card ‘ 𝑇 )  ↔  ∃ 𝑓 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 122 | 120 121 | sylib | ⊢ ( ( ∪  𝐴  ≈  𝑇  ∧  𝑇  ∈  Tarski )  →  ∃ 𝑓 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) | 
						
							| 123 | 122 | expcom | ⊢ ( 𝑇  ∈  Tarski  →  ( ∪  𝐴  ≈  𝑇  →  ∃ 𝑓 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) ) | 
						
							| 124 | 123 | 3ad2ant1 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ( ∪  𝐴  ≈  𝑇  →  ∃ 𝑓 𝑓 : ∪  𝐴 –1-1-onto→ ( card ‘ 𝑇 ) ) ) | 
						
							| 125 | 118 124 | mtod | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ¬  ∪  𝐴  ≈  𝑇 ) | 
						
							| 126 |  | uniss | ⊢ ( 𝐴  ⊆  𝑇  →  ∪  𝐴  ⊆  ∪  𝑇 ) | 
						
							| 127 |  | df-tr | ⊢ ( Tr  𝑇  ↔  ∪  𝑇  ⊆  𝑇 ) | 
						
							| 128 | 127 | biimpi | ⊢ ( Tr  𝑇  →  ∪  𝑇  ⊆  𝑇 ) | 
						
							| 129 | 126 128 | sylan9ss | ⊢ ( ( 𝐴  ⊆  𝑇  ∧  Tr  𝑇 )  →  ∪  𝐴  ⊆  𝑇 ) | 
						
							| 130 | 129 | expcom | ⊢ ( Tr  𝑇  →  ( 𝐴  ⊆  𝑇  →  ∪  𝐴  ⊆  𝑇 ) ) | 
						
							| 131 | 57 130 | syld | ⊢ ( Tr  𝑇  →  ( 𝐴  ∈  𝑇  →  ∪  𝐴  ⊆  𝑇 ) ) | 
						
							| 132 | 131 | imp | ⊢ ( ( Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ∪  𝐴  ⊆  𝑇 ) | 
						
							| 133 |  | tsken | ⊢ ( ( 𝑇  ∈  Tarski  ∧  ∪  𝐴  ⊆  𝑇 )  →  ( ∪  𝐴  ≈  𝑇  ∨  ∪  𝐴  ∈  𝑇 ) ) | 
						
							| 134 | 132 133 | sylan2 | ⊢ ( ( 𝑇  ∈  Tarski  ∧  ( Tr  𝑇  ∧  𝐴  ∈  𝑇 ) )  →  ( ∪  𝐴  ≈  𝑇  ∨  ∪  𝐴  ∈  𝑇 ) ) | 
						
							| 135 | 134 | 3impb | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ( ∪  𝐴  ≈  𝑇  ∨  ∪  𝐴  ∈  𝑇 ) ) | 
						
							| 136 | 135 | ord | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ( ¬  ∪  𝐴  ≈  𝑇  →  ∪  𝐴  ∈  𝑇 ) ) | 
						
							| 137 | 125 136 | mpd | ⊢ ( ( 𝑇  ∈  Tarski  ∧  Tr  𝑇  ∧  𝐴  ∈  𝑇 )  →  ∪  𝐴  ∈  𝑇 ) |