| Step | Hyp | Ref | Expression | 
						
							| 1 |  | coe1fval.a | ⊢ 𝐴  =  ( coe1 ‘ 𝐹 ) | 
						
							| 2 |  | coe1f2.b | ⊢ 𝐵  =  ( Base ‘ 𝑃 ) | 
						
							| 3 |  | coe1f2.p | ⊢ 𝑃  =  ( PwSer1 ‘ 𝑅 ) | 
						
							| 4 |  | coe1fval3.g | ⊢ 𝐺  =  ( 𝑦  ∈  ℕ0  ↦  ( 1o  ×  { 𝑦 } ) ) | 
						
							| 5 | 1 | coe1fval | ⊢ ( 𝐹  ∈  𝐵  →  𝐴  =  ( 𝑦  ∈  ℕ0  ↦  ( 𝐹 ‘ ( 1o  ×  { 𝑦 } ) ) ) ) | 
						
							| 6 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 7 | 3 2 6 | psr1basf | ⊢ ( 𝐹  ∈  𝐵  →  𝐹 : ( ℕ0  ↑m  1o ) ⟶ ( Base ‘ 𝑅 ) ) | 
						
							| 8 |  | ssv | ⊢ ( Base ‘ 𝑅 )  ⊆  V | 
						
							| 9 |  | fss | ⊢ ( ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ ( Base ‘ 𝑅 )  ∧  ( Base ‘ 𝑅 )  ⊆  V )  →  𝐹 : ( ℕ0  ↑m  1o ) ⟶ V ) | 
						
							| 10 | 7 8 9 | sylancl | ⊢ ( 𝐹  ∈  𝐵  →  𝐹 : ( ℕ0  ↑m  1o ) ⟶ V ) | 
						
							| 11 |  | fconst6g | ⊢ ( 𝑦  ∈  ℕ0  →  ( 1o  ×  { 𝑦 } ) : 1o ⟶ ℕ0 ) | 
						
							| 12 | 11 | adantl | ⊢ ( ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  ∧  𝑦  ∈  ℕ0 )  →  ( 1o  ×  { 𝑦 } ) : 1o ⟶ ℕ0 ) | 
						
							| 13 |  | nn0ex | ⊢ ℕ0  ∈  V | 
						
							| 14 |  | 1oex | ⊢ 1o  ∈  V | 
						
							| 15 | 13 14 | elmap | ⊢ ( ( 1o  ×  { 𝑦 } )  ∈  ( ℕ0  ↑m  1o )  ↔  ( 1o  ×  { 𝑦 } ) : 1o ⟶ ℕ0 ) | 
						
							| 16 | 12 15 | sylibr | ⊢ ( ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  ∧  𝑦  ∈  ℕ0 )  →  ( 1o  ×  { 𝑦 } )  ∈  ( ℕ0  ↑m  1o ) ) | 
						
							| 17 | 4 | a1i | ⊢ ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  →  𝐺  =  ( 𝑦  ∈  ℕ0  ↦  ( 1o  ×  { 𝑦 } ) ) ) | 
						
							| 18 |  | id | ⊢ ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  →  𝐹 : ( ℕ0  ↑m  1o ) ⟶ V ) | 
						
							| 19 | 18 | feqmptd | ⊢ ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  →  𝐹  =  ( 𝑥  ∈  ( ℕ0  ↑m  1o )  ↦  ( 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 20 |  | fveq2 | ⊢ ( 𝑥  =  ( 1o  ×  { 𝑦 } )  →  ( 𝐹 ‘ 𝑥 )  =  ( 𝐹 ‘ ( 1o  ×  { 𝑦 } ) ) ) | 
						
							| 21 | 16 17 19 20 | fmptco | ⊢ ( 𝐹 : ( ℕ0  ↑m  1o ) ⟶ V  →  ( 𝐹  ∘  𝐺 )  =  ( 𝑦  ∈  ℕ0  ↦  ( 𝐹 ‘ ( 1o  ×  { 𝑦 } ) ) ) ) | 
						
							| 22 | 10 21 | syl | ⊢ ( 𝐹  ∈  𝐵  →  ( 𝐹  ∘  𝐺 )  =  ( 𝑦  ∈  ℕ0  ↦  ( 𝐹 ‘ ( 1o  ×  { 𝑦 } ) ) ) ) | 
						
							| 23 | 5 22 | eqtr4d | ⊢ ( 𝐹  ∈  𝐵  →  𝐴  =  ( 𝐹  ∘  𝐺 ) ) |