| Step | Hyp | Ref | Expression | 
						
							| 1 |  | updjud.f | ⊢ ( 𝜑  →  𝐹 : 𝐴 ⟶ 𝐶 ) | 
						
							| 2 |  | updjud.g | ⊢ ( 𝜑  →  𝐺 : 𝐵 ⟶ 𝐶 ) | 
						
							| 3 |  | updjud.a | ⊢ ( 𝜑  →  𝐴  ∈  𝑉 ) | 
						
							| 4 |  | updjud.b | ⊢ ( 𝜑  →  𝐵  ∈  𝑊 ) | 
						
							| 5 | 3 4 | jca | ⊢ ( 𝜑  →  ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊 ) ) | 
						
							| 6 |  | djuex | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊 )  →  ( 𝐴  ⊔  𝐵 )  ∈  V ) | 
						
							| 7 |  | mptexg | ⊢ ( ( 𝐴  ⊔  𝐵 )  ∈  V  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∈  V ) | 
						
							| 8 | 5 6 7 | 3syl | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∈  V ) | 
						
							| 9 |  | feq1 | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ↔  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶 ) ) | 
						
							| 10 |  | coeq1 | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) ) ) | 
						
							| 11 | 10 | eqeq1d | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ↔  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹 ) ) | 
						
							| 12 |  | coeq1 | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) ) ) | 
						
							| 13 | 12 | eqeq1d | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  ↔  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 14 | 9 11 13 | 3anbi123d | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ↔  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) ) | 
						
							| 15 |  | eqeq1 | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ℎ  =  𝑘  ↔  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) | 
						
							| 16 | 15 | imbi2d | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 )  ↔  ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) | 
						
							| 17 | 16 | ralbidv | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 )  ↔  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) | 
						
							| 18 | 14 17 | anbi12d | ⊢ ( ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  →  ( ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 ) )  ↔  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) ) | 
						
							| 19 | 18 | adantl | ⊢ ( ( 𝜑  ∧  ℎ  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) )  →  ( ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 ) )  ↔  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) ) | 
						
							| 20 |  | eqid | ⊢ ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) | 
						
							| 21 | 1 2 20 | updjudhf | ⊢ ( 𝜑  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶 ) | 
						
							| 22 | 1 2 20 | updjudhcoinlf | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹 ) | 
						
							| 23 | 1 2 20 | updjudhcoinrg | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) | 
						
							| 24 |  | simpr | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 25 |  | eqeq2 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  ↔  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹 ) ) | 
						
							| 26 |  | fvres | ⊢ ( 𝑧  ∈  𝐴  →  ( ( inl  ↾  𝐴 ) ‘ 𝑧 )  =  ( inl ‘ 𝑧 ) ) | 
						
							| 27 | 26 | eqcomd | ⊢ ( 𝑧  ∈  𝐴  →  ( inl ‘ 𝑧 )  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) | 
						
							| 28 | 27 | eqeq2d | ⊢ ( 𝑧  ∈  𝐴  →  ( 𝑦  =  ( inl ‘ 𝑧 )  ↔  𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 29 | 28 | adantl | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( 𝑦  =  ( inl ‘ 𝑧 )  ↔  𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 30 |  | fveq1 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 ) ) | 
						
							| 31 | 30 | ad2antrr | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 ) ) | 
						
							| 32 |  | inlresf | ⊢ ( inl  ↾  𝐴 ) : 𝐴 ⟶ ( 𝐴  ⊔  𝐵 ) | 
						
							| 33 |  | ffn | ⊢ ( ( inl  ↾  𝐴 ) : 𝐴 ⟶ ( 𝐴  ⊔  𝐵 )  →  ( inl  ↾  𝐴 )  Fn  𝐴 ) | 
						
							| 34 | 32 33 | mp1i | ⊢ ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  →  ( inl  ↾  𝐴 )  Fn  𝐴 ) | 
						
							| 35 |  | fvco2 | ⊢ ( ( ( inl  ↾  𝐴 )  Fn  𝐴  ∧  𝑧  ∈  𝐴 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 36 | 34 35 | sylan | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 37 |  | fvco2 | ⊢ ( ( ( inl  ↾  𝐴 )  Fn  𝐴  ∧  𝑧  ∈  𝐴 )  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( 𝑘 ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 38 | 34 37 | sylan | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) ) ‘ 𝑧 )  =  ( 𝑘 ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 39 | 31 36 38 | 3eqtr3d | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) )  =  ( 𝑘 ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 40 |  | fveq2 | ⊢ ( 𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 41 |  | fveq2 | ⊢ ( 𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 )  →  ( 𝑘 ‘ 𝑦 )  =  ( 𝑘 ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) | 
						
							| 42 | 40 41 | eqeq12d | ⊢ ( 𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 )  ↔  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) )  =  ( 𝑘 ‘ ( ( inl  ↾  𝐴 ) ‘ 𝑧 ) ) ) ) | 
						
							| 43 | 39 42 | syl5ibrcom | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( 𝑦  =  ( ( inl  ↾  𝐴 ) ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 44 | 29 43 | sylbid | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐴 )  →  ( 𝑦  =  ( inl ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 45 | 44 | expimpd | ⊢ ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  ∧  𝜑 )  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 46 | 45 | ex | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 47 | 46 | eqcoms | ⊢ ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 48 | 25 47 | biimtrrdi | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 49 | 48 | com23 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( 𝜑  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 50 | 49 | 3ad2ant2 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝜑  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 51 | 50 | impcom | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 52 | 51 | com12 | ⊢ ( ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  →  ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 53 | 52 | 3ad2ant2 | ⊢ ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 54 | 53 | impcom | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 55 | 54 | com12 | ⊢ ( ( 𝑧  ∈  𝐴  ∧  𝑦  =  ( inl ‘ 𝑧 ) )  →  ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 56 | 55 | rexlimiva | ⊢ ( ∃ 𝑧  ∈  𝐴 𝑦  =  ( inl ‘ 𝑧 )  →  ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 57 |  | eqeq2 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  ↔  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 58 |  | fvres | ⊢ ( 𝑧  ∈  𝐵  →  ( ( inr  ↾  𝐵 ) ‘ 𝑧 )  =  ( inr ‘ 𝑧 ) ) | 
						
							| 59 | 58 | eqcomd | ⊢ ( 𝑧  ∈  𝐵  →  ( inr ‘ 𝑧 )  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) | 
						
							| 60 | 59 | eqeq2d | ⊢ ( 𝑧  ∈  𝐵  →  ( 𝑦  =  ( inr ‘ 𝑧 )  ↔  𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 61 | 60 | adantl | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( 𝑦  =  ( inr ‘ 𝑧 )  ↔  𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 62 |  | fveq1 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 ) ) | 
						
							| 63 | 62 | ad2antrr | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 ) ) | 
						
							| 64 |  | inrresf | ⊢ ( inr  ↾  𝐵 ) : 𝐵 ⟶ ( 𝐴  ⊔  𝐵 ) | 
						
							| 65 |  | ffn | ⊢ ( ( inr  ↾  𝐵 ) : 𝐵 ⟶ ( 𝐴  ⊔  𝐵 )  →  ( inr  ↾  𝐵 )  Fn  𝐵 ) | 
						
							| 66 | 64 65 | mp1i | ⊢ ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  →  ( inr  ↾  𝐵 )  Fn  𝐵 ) | 
						
							| 67 |  | fvco2 | ⊢ ( ( ( inr  ↾  𝐵 )  Fn  𝐵  ∧  𝑧  ∈  𝐵 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 68 | 66 67 | sylan | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 69 |  | fvco2 | ⊢ ( ( ( inr  ↾  𝐵 )  Fn  𝐵  ∧  𝑧  ∈  𝐵 )  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( 𝑘 ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 70 | 66 69 | sylan | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) ) ‘ 𝑧 )  =  ( 𝑘 ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 71 | 63 68 70 | 3eqtr3d | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) )  =  ( 𝑘 ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 72 |  | fveq2 | ⊢ ( 𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 73 |  | fveq2 | ⊢ ( 𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 )  →  ( 𝑘 ‘ 𝑦 )  =  ( 𝑘 ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) | 
						
							| 74 | 72 73 | eqeq12d | ⊢ ( 𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 )  ↔  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) )  =  ( 𝑘 ‘ ( ( inr  ↾  𝐵 ) ‘ 𝑧 ) ) ) ) | 
						
							| 75 | 71 74 | syl5ibrcom | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( 𝑦  =  ( ( inr  ↾  𝐵 ) ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 76 | 61 75 | sylbid | ⊢ ( ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  ∧  𝑧  ∈  𝐵 )  →  ( 𝑦  =  ( inr ‘ 𝑧 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 77 | 76 | expimpd | ⊢ ( ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  ∧  𝜑 )  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 78 | 77 | ex | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 79 | 78 | eqcoms | ⊢ ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 80 | 57 79 | biimtrrdi | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( 𝜑  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 81 | 80 | com23 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( 𝜑  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 82 | 81 | 3ad2ant3 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝜑  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) ) | 
						
							| 83 | 82 | impcom | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 84 | 83 | com12 | ⊢ ( ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  →  ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 85 | 84 | 3ad2ant3 | ⊢ ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) ) | 
						
							| 86 | 85 | impcom | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 87 | 86 | com12 | ⊢ ( ( 𝑧  ∈  𝐵  ∧  𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 88 | 87 | rexlimiva | ⊢ ( ∃ 𝑧  ∈  𝐵 𝑦  =  ( inr ‘ 𝑧 )  →  ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 89 | 56 88 | jaoi | ⊢ ( ( ∃ 𝑧  ∈  𝐴 𝑦  =  ( inl ‘ 𝑧 )  ∨  ∃ 𝑧  ∈  𝐵 𝑦  =  ( inr ‘ 𝑧 ) )  →  ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 90 |  | djur | ⊢ ( 𝑦  ∈  ( 𝐴  ⊔  𝐵 )  →  ( ∃ 𝑧  ∈  𝐴 𝑦  =  ( inl ‘ 𝑧 )  ∨  ∃ 𝑧  ∈  𝐵 𝑦  =  ( inr ‘ 𝑧 ) ) ) | 
						
							| 91 | 89 90 | syl11 | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( 𝑦  ∈  ( 𝐴  ⊔  𝐵 )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 92 | 91 | ralrimiv | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ∀ 𝑦  ∈  ( 𝐴  ⊔  𝐵 ) ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) | 
						
							| 93 |  | ffn | ⊢ ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  Fn  ( 𝐴  ⊔  𝐵 ) ) | 
						
							| 94 | 93 | 3ad2ant1 | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  Fn  ( 𝐴  ⊔  𝐵 ) ) | 
						
							| 95 | 94 | adantl | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  Fn  ( 𝐴  ⊔  𝐵 ) ) | 
						
							| 96 |  | ffn | ⊢ ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  →  𝑘  Fn  ( 𝐴  ⊔  𝐵 ) ) | 
						
							| 97 | 96 | 3ad2ant1 | ⊢ ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  𝑘  Fn  ( 𝐴  ⊔  𝐵 ) ) | 
						
							| 98 |  | eqfnfv | ⊢ ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  Fn  ( 𝐴  ⊔  𝐵 )  ∧  𝑘  Fn  ( 𝐴  ⊔  𝐵 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘  ↔  ∀ 𝑦  ∈  ( 𝐴  ⊔  𝐵 ) ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 99 | 95 97 98 | syl2an | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘  ↔  ∀ 𝑦  ∈  ( 𝐴  ⊔  𝐵 ) ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) ‘ 𝑦 )  =  ( 𝑘 ‘ 𝑦 ) ) ) | 
						
							| 100 | 92 99 | mpbird | ⊢ ( ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  ∧  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) | 
						
							| 101 | 100 | ex | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) | 
						
							| 102 | 101 | ralrimivw | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) | 
						
							| 103 | 24 102 | jca | ⊢ ( ( 𝜑  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) | 
						
							| 104 | 103 | ex | ⊢ ( 𝜑  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) ) | 
						
							| 105 | 21 22 23 104 | mp3and | ⊢ ( 𝜑  →  ( ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) ) : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ( 𝑥  ∈  ( 𝐴  ⊔  𝐵 )  ↦  if ( ( 1st  ‘ 𝑥 )  =  ∅ ,  ( 𝐹 ‘ ( 2nd  ‘ 𝑥 ) ) ,  ( 𝐺 ‘ ( 2nd  ‘ 𝑥 ) ) ) )  =  𝑘 ) ) ) | 
						
							| 106 | 8 19 105 | rspcedvd | ⊢ ( 𝜑  →  ∃ ℎ  ∈  V ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 ) ) ) | 
						
							| 107 |  | feq1 | ⊢ ( ℎ  =  𝑘  →  ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ↔  𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶 ) ) | 
						
							| 108 |  | coeq1 | ⊢ ( ℎ  =  𝑘  →  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  ( 𝑘  ∘  ( inl  ↾  𝐴 ) ) ) | 
						
							| 109 | 108 | eqeq1d | ⊢ ( ℎ  =  𝑘  →  ( ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ↔  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹 ) ) | 
						
							| 110 |  | coeq1 | ⊢ ( ℎ  =  𝑘  →  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  ( 𝑘  ∘  ( inr  ↾  𝐵 ) ) ) | 
						
							| 111 | 110 | eqeq1d | ⊢ ( ℎ  =  𝑘  →  ( ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺  ↔  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 112 | 107 109 111 | 3anbi123d | ⊢ ( ℎ  =  𝑘  →  ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ↔  ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) ) | 
						
							| 113 | 112 | reu8 | ⊢ ( ∃! ℎ  ∈  V ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ↔  ∃ ℎ  ∈  V ( ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ∧  ∀ 𝑘  ∈  V ( ( 𝑘 : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( 𝑘  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( 𝑘  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  →  ℎ  =  𝑘 ) ) ) | 
						
							| 114 | 106 113 | sylibr | ⊢ ( 𝜑  →  ∃! ℎ  ∈  V ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 115 |  | reuv | ⊢ ( ∃! ℎ  ∈  V ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 )  ↔  ∃! ℎ ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) | 
						
							| 116 | 114 115 | sylib | ⊢ ( 𝜑  →  ∃! ℎ ( ℎ : ( 𝐴  ⊔  𝐵 ) ⟶ 𝐶  ∧  ( ℎ  ∘  ( inl  ↾  𝐴 ) )  =  𝐹  ∧  ( ℎ  ∘  ( inr  ↾  𝐵 ) )  =  𝐺 ) ) |