| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fsplitfpar.h | ⊢ 𝐻  =  ( ( ◡ ( 1st   ↾  ( V  ×  V ) )  ∘  ( 𝐹  ∘  ( 1st   ↾  ( V  ×  V ) ) ) )  ∩  ( ◡ ( 2nd   ↾  ( V  ×  V ) )  ∘  ( 𝐺  ∘  ( 2nd   ↾  ( V  ×  V ) ) ) ) ) | 
						
							| 2 |  | fsplitfpar.s | ⊢ 𝑆  =  ( ◡ ( 1st   ↾   I  )  ↾  𝐴 ) | 
						
							| 3 | 1 2 | fsplitfpar | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  →  ( 𝐻  ∘  𝑆 )  =  ( 𝑎  ∈  𝐴  ↦  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) ) | 
						
							| 4 | 3 | coeq2d | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  →  (  +   ∘  ( 𝐻  ∘  𝑆 ) )  =  (  +   ∘  ( 𝑎  ∈  𝐴  ↦  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) ) ) | 
						
							| 5 | 4 | 3ad2ant1 | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  (  +   ∘  ( 𝐻  ∘  𝑆 ) )  =  (  +   ∘  ( 𝑎  ∈  𝐴  ↦  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) ) ) | 
						
							| 6 |  | dffn3 | ⊢ (  +   Fn  𝐶  ↔   +  : 𝐶 ⟶ ran   +  ) | 
						
							| 7 | 6 | biimpi | ⊢ (  +   Fn  𝐶  →   +  : 𝐶 ⟶ ran   +  ) | 
						
							| 8 | 7 | adantr | ⊢ ( (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 )  →   +  : 𝐶 ⟶ ran   +  ) | 
						
							| 9 | 8 | 3ad2ant3 | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →   +  : 𝐶 ⟶ ran   +  ) | 
						
							| 10 |  | simpl3r | ⊢ ( ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  ∧  𝑎  ∈  𝐴 )  →  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) | 
						
							| 11 |  | simp1l | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  𝐹  Fn  𝐴 ) | 
						
							| 12 |  | fnfvelrn | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝑎  ∈  𝐴 )  →  ( 𝐹 ‘ 𝑎 )  ∈  ran  𝐹 ) | 
						
							| 13 | 11 12 | sylan | ⊢ ( ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  ∧  𝑎  ∈  𝐴 )  →  ( 𝐹 ‘ 𝑎 )  ∈  ran  𝐹 ) | 
						
							| 14 |  | simp1r | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  𝐺  Fn  𝐴 ) | 
						
							| 15 |  | fnfvelrn | ⊢ ( ( 𝐺  Fn  𝐴  ∧  𝑎  ∈  𝐴 )  →  ( 𝐺 ‘ 𝑎 )  ∈  ran  𝐺 ) | 
						
							| 16 | 14 15 | sylan | ⊢ ( ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  ∧  𝑎  ∈  𝐴 )  →  ( 𝐺 ‘ 𝑎 )  ∈  ran  𝐺 ) | 
						
							| 17 | 13 16 | opelxpd | ⊢ ( ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  ∧  𝑎  ∈  𝐴 )  →  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉  ∈  ( ran  𝐹  ×  ran  𝐺 ) ) | 
						
							| 18 | 10 17 | sseldd | ⊢ ( ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  ∧  𝑎  ∈  𝐴 )  →  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉  ∈  𝐶 ) | 
						
							| 19 | 9 18 | cofmpt | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  (  +   ∘  ( 𝑎  ∈  𝐴  ↦  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) )  =  ( 𝑎  ∈  𝐴  ↦  (  +  ‘ 〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) ) ) | 
						
							| 20 |  | df-ov | ⊢ ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) )  =  (  +  ‘ 〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) | 
						
							| 21 | 20 | eqcomi | ⊢ (  +  ‘ 〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 )  =  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) | 
						
							| 22 | 21 | mpteq2i | ⊢ ( 𝑎  ∈  𝐴  ↦  (  +  ‘ 〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) )  =  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) ) | 
						
							| 23 | 19 22 | eqtrdi | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  (  +   ∘  ( 𝑎  ∈  𝐴  ↦  〈 ( 𝐹 ‘ 𝑎 ) ,  ( 𝐺 ‘ 𝑎 ) 〉 ) )  =  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) ) ) | 
						
							| 24 |  | offval3 | ⊢ ( ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  →  ( 𝐹  ∘f   +  𝐺 )  =  ( 𝑎  ∈  ( dom  𝐹  ∩  dom  𝐺 )  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) ) ) | 
						
							| 25 |  | fndm | ⊢ ( 𝐹  Fn  𝐴  →  dom  𝐹  =  𝐴 ) | 
						
							| 26 |  | fndm | ⊢ ( 𝐺  Fn  𝐴  →  dom  𝐺  =  𝐴 ) | 
						
							| 27 | 25 26 | ineqan12d | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  →  ( dom  𝐹  ∩  dom  𝐺 )  =  ( 𝐴  ∩  𝐴 ) ) | 
						
							| 28 |  | inidm | ⊢ ( 𝐴  ∩  𝐴 )  =  𝐴 | 
						
							| 29 | 27 28 | eqtrdi | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  →  ( dom  𝐹  ∩  dom  𝐺 )  =  𝐴 ) | 
						
							| 30 | 29 | mpteq1d | ⊢ ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  →  ( 𝑎  ∈  ( dom  𝐹  ∩  dom  𝐺 )  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) )  =  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) ) ) | 
						
							| 31 | 24 30 | sylan9eqr | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 ) )  →  ( 𝐹  ∘f   +  𝐺 )  =  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) ) ) | 
						
							| 32 | 31 | eqcomd | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 ) )  →  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) )  =  ( 𝐹  ∘f   +  𝐺 ) ) | 
						
							| 33 | 32 | 3adant3 | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  ( 𝑎  ∈  𝐴  ↦  ( ( 𝐹 ‘ 𝑎 )  +  ( 𝐺 ‘ 𝑎 ) ) )  =  ( 𝐹  ∘f   +  𝐺 ) ) | 
						
							| 34 | 5 23 33 | 3eqtrd | ⊢ ( ( ( 𝐹  Fn  𝐴  ∧  𝐺  Fn  𝐴 )  ∧  ( 𝐹  ∈  𝑉  ∧  𝐺  ∈  𝑊 )  ∧  (  +   Fn  𝐶  ∧  ( ran  𝐹  ×  ran  𝐺 )  ⊆  𝐶 ) )  →  (  +   ∘  ( 𝐻  ∘  𝑆 ) )  =  ( 𝐹  ∘f   +  𝐺 ) ) |