Metamath Proof Explorer


Theorem satf0suc

Description: The value of the satisfaction predicate as function over wff codes in the empty model and the empty binary relation at a successor. (Contributed by AV, 19-Sep-2023)

Ref Expression
Hypothesis satf0suc.s 𝑆 = ( ∅ Sat ∅ )
Assertion satf0suc ( 𝑁 ∈ ω → ( 𝑆 ‘ suc 𝑁 ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )

Proof

Step Hyp Ref Expression
1 satf0suc.s 𝑆 = ( ∅ Sat ∅ )
2 1 fveq1i ( 𝑆 ‘ suc 𝑁 ) = ( ( ∅ Sat ∅ ) ‘ suc 𝑁 )
3 2 a1i ( 𝑁 ∈ ω → ( 𝑆 ‘ suc 𝑁 ) = ( ( ∅ Sat ∅ ) ‘ suc 𝑁 ) )
4 omsucelsucb ( 𝑁 ∈ ω ↔ suc 𝑁 ∈ suc ω )
5 satf0sucom ( suc 𝑁 ∈ suc ω → ( ( ∅ Sat ∅ ) ‘ suc 𝑁 ) = ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ suc 𝑁 ) )
6 4 5 sylbi ( 𝑁 ∈ ω → ( ( ∅ Sat ∅ ) ‘ suc 𝑁 ) = ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ suc 𝑁 ) )
7 nnon ( 𝑁 ∈ ω → 𝑁 ∈ On )
8 rdgsuc ( 𝑁 ∈ On → ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ suc 𝑁 ) = ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) )
9 7 8 syl ( 𝑁 ∈ ω → ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ suc 𝑁 ) = ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) )
10 1 eqcomi ( ∅ Sat ∅ ) = 𝑆
11 10 fveq1i ( ( ∅ Sat ∅ ) ‘ 𝑁 ) = ( 𝑆𝑁 )
12 elelsuc ( 𝑁 ∈ ω → 𝑁 ∈ suc ω )
13 satf0sucom ( 𝑁 ∈ suc ω → ( ( ∅ Sat ∅ ) ‘ 𝑁 ) = ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) )
14 12 13 syl ( 𝑁 ∈ ω → ( ( ∅ Sat ∅ ) ‘ 𝑁 ) = ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) )
15 11 14 syl5reqr ( 𝑁 ∈ ω → ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) = ( 𝑆𝑁 ) )
16 15 fveq2d ( 𝑁 ∈ ω → ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) ‘ ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ 𝑁 ) ) = ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) ‘ ( 𝑆𝑁 ) ) )
17 eqidd ( 𝑁 ∈ ω → ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) = ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) )
18 id ( 𝑓 = ( 𝑆𝑁 ) → 𝑓 = ( 𝑆𝑁 ) )
19 rexeq ( 𝑓 = ( 𝑆𝑁 ) → ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ↔ ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ) )
20 19 orbi1d ( 𝑓 = ( 𝑆𝑁 ) → ( ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ↔ ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) )
21 20 rexeqbi1dv ( 𝑓 = ( 𝑆𝑁 ) → ( ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ↔ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) )
22 21 anbi2d ( 𝑓 = ( 𝑆𝑁 ) → ( ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) ↔ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) ) )
23 22 opabbidv ( 𝑓 = ( 𝑆𝑁 ) → { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } )
24 18 23 uneq12d ( 𝑓 = ( 𝑆𝑁 ) → ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )
25 24 adantl ( ( 𝑁 ∈ ω ∧ 𝑓 = ( 𝑆𝑁 ) ) → ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )
26 fvex ( 𝑆𝑁 ) ∈ V
27 26 a1i ( 𝑁 ∈ ω → ( 𝑆𝑁 ) ∈ V )
28 omex ω ∈ V
29 satf0suclem ( ( ( 𝑆𝑁 ) ∈ V ∧ ( 𝑆𝑁 ) ∈ V ∧ ω ∈ V ) → { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ∈ V )
30 26 26 28 29 mp3an { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ∈ V
31 26 30 unex ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ∈ V
32 31 a1i ( 𝑁 ∈ ω → ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ∈ V )
33 17 25 27 32 fvmptd ( 𝑁 ∈ ω → ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) ‘ ( 𝑆𝑁 ) ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )
34 9 16 33 3eqtrd ( 𝑁 ∈ ω → ( rec ( ( 𝑓 ∈ V ↦ ( 𝑓 ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢𝑓 ( ∃ 𝑣𝑓 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) ) , { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑖 ∈ ω ∃ 𝑗 ∈ ω 𝑥 = ( 𝑖𝑔 𝑗 ) ) } ) ‘ suc 𝑁 ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )
35 3 6 34 3eqtrd ( 𝑁 ∈ ω → ( 𝑆 ‘ suc 𝑁 ) = ( ( 𝑆𝑁 ) ∪ { ⟨ 𝑥 , 𝑦 ⟩ ∣ ( 𝑦 = ∅ ∧ ∃ 𝑢 ∈ ( 𝑆𝑁 ) ( ∃ 𝑣 ∈ ( 𝑆𝑁 ) 𝑥 = ( ( 1st𝑢 ) ⊼𝑔 ( 1st𝑣 ) ) ∨ ∃ 𝑖 ∈ ω 𝑥 = ∀𝑔 𝑖 ( 1st𝑢 ) ) ) } ) )