| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oef1o.f | ⊢ ( 𝜑  →  𝐹 : 𝐴 –1-1-onto→ 𝐶 ) | 
						
							| 2 |  | oef1o.g | ⊢ ( 𝜑  →  𝐺 : 𝐵 –1-1-onto→ 𝐷 ) | 
						
							| 3 |  | oef1o.a | ⊢ ( 𝜑  →  𝐴  ∈  ( On  ∖  1o ) ) | 
						
							| 4 |  | oef1o.b | ⊢ ( 𝜑  →  𝐵  ∈  On ) | 
						
							| 5 |  | oef1o.c | ⊢ ( 𝜑  →  𝐶  ∈  On ) | 
						
							| 6 |  | oef1o.d | ⊢ ( 𝜑  →  𝐷  ∈  On ) | 
						
							| 7 |  | oef1o.z | ⊢ ( 𝜑  →  ( 𝐹 ‘ ∅ )  =  ∅ ) | 
						
							| 8 |  | oef1o.k | ⊢ 𝐾  =  ( 𝑦  ∈  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  ↦  ( 𝐹  ∘  ( 𝑦  ∘  ◡ 𝐺 ) ) ) | 
						
							| 9 |  | oef1o.h | ⊢ 𝐻  =  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) ) | 
						
							| 10 |  | eqid | ⊢ dom  ( 𝐶  CNF  𝐷 )  =  dom  ( 𝐶  CNF  𝐷 ) | 
						
							| 11 | 10 5 6 | cantnff1o | ⊢ ( 𝜑  →  ( 𝐶  CNF  𝐷 ) : dom  ( 𝐶  CNF  𝐷 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 12 |  | eqid | ⊢ { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  =  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } | 
						
							| 13 |  | eqid | ⊢ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) }  =  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } | 
						
							| 14 |  | eqid | ⊢ ( 𝐹 ‘ ∅ )  =  ( 𝐹 ‘ ∅ ) | 
						
							| 15 |  | f1ocnv | ⊢ ( 𝐺 : 𝐵 –1-1-onto→ 𝐷  →  ◡ 𝐺 : 𝐷 –1-1-onto→ 𝐵 ) | 
						
							| 16 | 2 15 | syl | ⊢ ( 𝜑  →  ◡ 𝐺 : 𝐷 –1-1-onto→ 𝐵 ) | 
						
							| 17 |  | ondif1 | ⊢ ( 𝐴  ∈  ( On  ∖  1o )  ↔  ( 𝐴  ∈  On  ∧  ∅  ∈  𝐴 ) ) | 
						
							| 18 | 17 | simprbi | ⊢ ( 𝐴  ∈  ( On  ∖  1o )  →  ∅  ∈  𝐴 ) | 
						
							| 19 | 3 18 | syl | ⊢ ( 𝜑  →  ∅  ∈  𝐴 ) | 
						
							| 20 | 12 13 14 16 1 4 3 6 5 19 | mapfien | ⊢ ( 𝜑  →  ( 𝑦  ∈  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  ↦  ( 𝐹  ∘  ( 𝑦  ∘  ◡ 𝐺 ) ) ) : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) | 
						
							| 21 |  | f1oeq1 | ⊢ ( 𝐾  =  ( 𝑦  ∈  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  ↦  ( 𝐹  ∘  ( 𝑦  ∘  ◡ 𝐺 ) ) )  →  ( 𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) }  ↔  ( 𝑦  ∈  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  ↦  ( 𝐹  ∘  ( 𝑦  ∘  ◡ 𝐺 ) ) ) : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) ) | 
						
							| 22 | 8 21 | ax-mp | ⊢ ( 𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) }  ↔  ( 𝑦  ∈  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ }  ↦  ( 𝐹  ∘  ( 𝑦  ∘  ◡ 𝐺 ) ) ) : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) | 
						
							| 23 | 20 22 | sylibr | ⊢ ( 𝜑  →  𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) | 
						
							| 24 |  | eqid | ⊢ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ∅ }  =  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ∅ } | 
						
							| 25 | 24 5 6 | cantnfdm | ⊢ ( 𝜑  →  dom  ( 𝐶  CNF  𝐷 )  =  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ∅ } ) | 
						
							| 26 | 7 | breq2d | ⊢ ( 𝜑  →  ( 𝑥  finSupp  ( 𝐹 ‘ ∅ )  ↔  𝑥  finSupp  ∅ ) ) | 
						
							| 27 | 26 | rabbidv | ⊢ ( 𝜑  →  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) }  =  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ∅ } ) | 
						
							| 28 | 25 27 | eqtr4d | ⊢ ( 𝜑  →  dom  ( 𝐶  CNF  𝐷 )  =  { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) | 
						
							| 29 | 28 | f1oeq3d | ⊢ ( 𝜑  →  ( 𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ dom  ( 𝐶  CNF  𝐷 )  ↔  𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ { 𝑥  ∈  ( 𝐶  ↑m  𝐷 )  ∣  𝑥  finSupp  ( 𝐹 ‘ ∅ ) } ) ) | 
						
							| 30 | 23 29 | mpbird | ⊢ ( 𝜑  →  𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ dom  ( 𝐶  CNF  𝐷 ) ) | 
						
							| 31 | 3 | eldifad | ⊢ ( 𝜑  →  𝐴  ∈  On ) | 
						
							| 32 | 12 31 4 | cantnfdm | ⊢ ( 𝜑  →  dom  ( 𝐴  CNF  𝐵 )  =  { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } ) | 
						
							| 33 | 32 | f1oeq2d | ⊢ ( 𝜑  →  ( 𝐾 : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ dom  ( 𝐶  CNF  𝐷 )  ↔  𝐾 : { 𝑥  ∈  ( 𝐴  ↑m  𝐵 )  ∣  𝑥  finSupp  ∅ } –1-1-onto→ dom  ( 𝐶  CNF  𝐷 ) ) ) | 
						
							| 34 | 30 33 | mpbird | ⊢ ( 𝜑  →  𝐾 : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ dom  ( 𝐶  CNF  𝐷 ) ) | 
						
							| 35 |  | f1oco | ⊢ ( ( ( 𝐶  CNF  𝐷 ) : dom  ( 𝐶  CNF  𝐷 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 )  ∧  𝐾 : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ dom  ( 𝐶  CNF  𝐷 ) )  →  ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 ) : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 36 | 11 34 35 | syl2anc | ⊢ ( 𝜑  →  ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 ) : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 37 |  | eqid | ⊢ dom  ( 𝐴  CNF  𝐵 )  =  dom  ( 𝐴  CNF  𝐵 ) | 
						
							| 38 | 37 31 4 | cantnff1o | ⊢ ( 𝜑  →  ( 𝐴  CNF  𝐵 ) : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ ( 𝐴  ↑o  𝐵 ) ) | 
						
							| 39 |  | f1ocnv | ⊢ ( ( 𝐴  CNF  𝐵 ) : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ ( 𝐴  ↑o  𝐵 )  →  ◡ ( 𝐴  CNF  𝐵 ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ dom  ( 𝐴  CNF  𝐵 ) ) | 
						
							| 40 | 38 39 | syl | ⊢ ( 𝜑  →  ◡ ( 𝐴  CNF  𝐵 ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ dom  ( 𝐴  CNF  𝐵 ) ) | 
						
							| 41 |  | f1oco | ⊢ ( ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 ) : dom  ( 𝐴  CNF  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 )  ∧  ◡ ( 𝐴  CNF  𝐵 ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ dom  ( 𝐴  CNF  𝐵 ) )  →  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 42 | 36 40 41 | syl2anc | ⊢ ( 𝜑  →  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 43 |  | f1oeq1 | ⊢ ( 𝐻  =  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) )  →  ( 𝐻 : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 )  ↔  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) ) | 
						
							| 44 | 9 43 | ax-mp | ⊢ ( 𝐻 : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 )  ↔  ( ( ( 𝐶  CNF  𝐷 )  ∘  𝐾 )  ∘  ◡ ( 𝐴  CNF  𝐵 ) ) : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) | 
						
							| 45 | 42 44 | sylibr | ⊢ ( 𝜑  →  𝐻 : ( 𝐴  ↑o  𝐵 ) –1-1-onto→ ( 𝐶  ↑o  𝐷 ) ) |