| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-sate | ⊢  Sat∈   =  ( 𝑚  ∈  V ,  𝑢  ∈  V  ↦  ( ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω ) ‘ 𝑢 ) ) | 
						
							| 2 | 1 | a1i | ⊢ ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  →   Sat∈   =  ( 𝑚  ∈  V ,  𝑢  ∈  V  ↦  ( ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω ) ‘ 𝑢 ) ) ) | 
						
							| 3 |  | id | ⊢ ( 𝑚  =  𝑀  →  𝑚  =  𝑀 ) | 
						
							| 4 | 3 | sqxpeqd | ⊢ ( 𝑚  =  𝑀  →  ( 𝑚  ×  𝑚 )  =  ( 𝑀  ×  𝑀 ) ) | 
						
							| 5 | 4 | ineq2d | ⊢ ( 𝑚  =  𝑀  →  (  E   ∩  ( 𝑚  ×  𝑚 ) )  =  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) | 
						
							| 6 | 3 5 | oveq12d | ⊢ ( 𝑚  =  𝑀  →  ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) )  =  ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ) | 
						
							| 7 | 6 | fveq1d | ⊢ ( 𝑚  =  𝑀  →  ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω )  =  ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ) | 
						
							| 8 | 7 | adantr | ⊢ ( ( 𝑚  =  𝑀  ∧  𝑢  =  𝑈 )  →  ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω )  =  ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ) | 
						
							| 9 |  | simpr | ⊢ ( ( 𝑚  =  𝑀  ∧  𝑢  =  𝑈 )  →  𝑢  =  𝑈 ) | 
						
							| 10 | 8 9 | fveq12d | ⊢ ( ( 𝑚  =  𝑀  ∧  𝑢  =  𝑈 )  →  ( ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω ) ‘ 𝑢 )  =  ( ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ‘ 𝑈 ) ) | 
						
							| 11 | 10 | adantl | ⊢ ( ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  ∧  ( 𝑚  =  𝑀  ∧  𝑢  =  𝑈 ) )  →  ( ( ( 𝑚  Sat  (  E   ∩  ( 𝑚  ×  𝑚 ) ) ) ‘ ω ) ‘ 𝑢 )  =  ( ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ‘ 𝑈 ) ) | 
						
							| 12 |  | elex | ⊢ ( 𝑀  ∈  𝑉  →  𝑀  ∈  V ) | 
						
							| 13 | 12 | adantr | ⊢ ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  →  𝑀  ∈  V ) | 
						
							| 14 |  | elex | ⊢ ( 𝑈  ∈  𝑊  →  𝑈  ∈  V ) | 
						
							| 15 | 14 | adantl | ⊢ ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  →  𝑈  ∈  V ) | 
						
							| 16 |  | fvexd | ⊢ ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  →  ( ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ‘ 𝑈 )  ∈  V ) | 
						
							| 17 | 2 11 13 15 16 | ovmpod | ⊢ ( ( 𝑀  ∈  𝑉  ∧  𝑈  ∈  𝑊 )  →  ( 𝑀  Sat∈  𝑈 )  =  ( ( ( 𝑀  Sat  (  E   ∩  ( 𝑀  ×  𝑀 ) ) ) ‘ ω ) ‘ 𝑈 ) ) |