| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cantnfs.s | ⊢ 𝑆  =  dom  ( 𝐴  CNF  𝐵 ) | 
						
							| 2 |  | cantnfs.a | ⊢ ( 𝜑  →  𝐴  ∈  On ) | 
						
							| 3 |  | cantnfs.b | ⊢ ( 𝜑  →  𝐵  ∈  On ) | 
						
							| 4 |  | oemapval.t | ⊢ 𝑇  =  { 〈 𝑥 ,  𝑦 〉  ∣  ∃ 𝑧  ∈  𝐵 ( ( 𝑥 ‘ 𝑧 )  ∈  ( 𝑦 ‘ 𝑧 )  ∧  ∀ 𝑤  ∈  𝐵 ( 𝑧  ∈  𝑤  →  ( 𝑥 ‘ 𝑤 )  =  ( 𝑦 ‘ 𝑤 ) ) ) } | 
						
							| 5 |  | cantnf.c | ⊢ ( 𝜑  →  𝐶  ∈  ( 𝐴  ↑o  𝐵 ) ) | 
						
							| 6 |  | cantnf.s | ⊢ ( 𝜑  →  𝐶  ⊆  ran  ( 𝐴  CNF  𝐵 ) ) | 
						
							| 7 |  | cantnf.e | ⊢ ( 𝜑  →  ∅  ∈  𝐶 ) | 
						
							| 8 |  | oecl | ⊢ ( ( 𝐴  ∈  On  ∧  𝐵  ∈  On )  →  ( 𝐴  ↑o  𝐵 )  ∈  On ) | 
						
							| 9 | 2 3 8 | syl2anc | ⊢ ( 𝜑  →  ( 𝐴  ↑o  𝐵 )  ∈  On ) | 
						
							| 10 |  | onelon | ⊢ ( ( ( 𝐴  ↑o  𝐵 )  ∈  On  ∧  𝐶  ∈  ( 𝐴  ↑o  𝐵 ) )  →  𝐶  ∈  On ) | 
						
							| 11 | 9 5 10 | syl2anc | ⊢ ( 𝜑  →  𝐶  ∈  On ) | 
						
							| 12 |  | ondif1 | ⊢ ( 𝐶  ∈  ( On  ∖  1o )  ↔  ( 𝐶  ∈  On  ∧  ∅  ∈  𝐶 ) ) | 
						
							| 13 | 11 7 12 | sylanbrc | ⊢ ( 𝜑  →  𝐶  ∈  ( On  ∖  1o ) ) | 
						
							| 14 | 13 | eldifbd | ⊢ ( 𝜑  →  ¬  𝐶  ∈  1o ) | 
						
							| 15 |  | ssel | ⊢ ( ( 𝐴  ↑o  𝐵 )  ⊆  1o  →  ( 𝐶  ∈  ( 𝐴  ↑o  𝐵 )  →  𝐶  ∈  1o ) ) | 
						
							| 16 | 5 15 | syl5com | ⊢ ( 𝜑  →  ( ( 𝐴  ↑o  𝐵 )  ⊆  1o  →  𝐶  ∈  1o ) ) | 
						
							| 17 | 14 16 | mtod | ⊢ ( 𝜑  →  ¬  ( 𝐴  ↑o  𝐵 )  ⊆  1o ) | 
						
							| 18 |  | oe0m | ⊢ ( 𝐵  ∈  On  →  ( ∅  ↑o  𝐵 )  =  ( 1o  ∖  𝐵 ) ) | 
						
							| 19 | 3 18 | syl | ⊢ ( 𝜑  →  ( ∅  ↑o  𝐵 )  =  ( 1o  ∖  𝐵 ) ) | 
						
							| 20 |  | difss | ⊢ ( 1o  ∖  𝐵 )  ⊆  1o | 
						
							| 21 | 19 20 | eqsstrdi | ⊢ ( 𝜑  →  ( ∅  ↑o  𝐵 )  ⊆  1o ) | 
						
							| 22 |  | oveq1 | ⊢ ( 𝐴  =  ∅  →  ( 𝐴  ↑o  𝐵 )  =  ( ∅  ↑o  𝐵 ) ) | 
						
							| 23 | 22 | sseq1d | ⊢ ( 𝐴  =  ∅  →  ( ( 𝐴  ↑o  𝐵 )  ⊆  1o  ↔  ( ∅  ↑o  𝐵 )  ⊆  1o ) ) | 
						
							| 24 | 21 23 | syl5ibrcom | ⊢ ( 𝜑  →  ( 𝐴  =  ∅  →  ( 𝐴  ↑o  𝐵 )  ⊆  1o ) ) | 
						
							| 25 |  | oe1m | ⊢ ( 𝐵  ∈  On  →  ( 1o  ↑o  𝐵 )  =  1o ) | 
						
							| 26 |  | eqimss | ⊢ ( ( 1o  ↑o  𝐵 )  =  1o  →  ( 1o  ↑o  𝐵 )  ⊆  1o ) | 
						
							| 27 | 3 25 26 | 3syl | ⊢ ( 𝜑  →  ( 1o  ↑o  𝐵 )  ⊆  1o ) | 
						
							| 28 |  | oveq1 | ⊢ ( 𝐴  =  1o  →  ( 𝐴  ↑o  𝐵 )  =  ( 1o  ↑o  𝐵 ) ) | 
						
							| 29 | 28 | sseq1d | ⊢ ( 𝐴  =  1o  →  ( ( 𝐴  ↑o  𝐵 )  ⊆  1o  ↔  ( 1o  ↑o  𝐵 )  ⊆  1o ) ) | 
						
							| 30 | 27 29 | syl5ibrcom | ⊢ ( 𝜑  →  ( 𝐴  =  1o  →  ( 𝐴  ↑o  𝐵 )  ⊆  1o ) ) | 
						
							| 31 | 24 30 | jaod | ⊢ ( 𝜑  →  ( ( 𝐴  =  ∅  ∨  𝐴  =  1o )  →  ( 𝐴  ↑o  𝐵 )  ⊆  1o ) ) | 
						
							| 32 | 17 31 | mtod | ⊢ ( 𝜑  →  ¬  ( 𝐴  =  ∅  ∨  𝐴  =  1o ) ) | 
						
							| 33 |  | elpri | ⊢ ( 𝐴  ∈  { ∅ ,  1o }  →  ( 𝐴  =  ∅  ∨  𝐴  =  1o ) ) | 
						
							| 34 |  | df2o3 | ⊢ 2o  =  { ∅ ,  1o } | 
						
							| 35 | 33 34 | eleq2s | ⊢ ( 𝐴  ∈  2o  →  ( 𝐴  =  ∅  ∨  𝐴  =  1o ) ) | 
						
							| 36 | 32 35 | nsyl | ⊢ ( 𝜑  →  ¬  𝐴  ∈  2o ) | 
						
							| 37 | 2 36 | eldifd | ⊢ ( 𝜑  →  𝐴  ∈  ( On  ∖  2o ) ) | 
						
							| 38 | 37 13 | jca | ⊢ ( 𝜑  →  ( 𝐴  ∈  ( On  ∖  2o )  ∧  𝐶  ∈  ( On  ∖  1o ) ) ) |