Metamath Proof Explorer


Theorem satf00

Description: The value of the satisfaction predicate as function over wff codes in the empty model with an empty binary relation at (/) . (Contributed by AV, 14-Sep-2023)

Ref Expression
Assertion satf00 Sat = x y | y = i ω j ω x = i 𝑔 j

Proof

Step Hyp Ref Expression
1 peano1 ω
2 elelsuc ω suc ω
3 satf0sucom suc ω Sat = rec f V f x y | y = u f v f x = 1 st u 𝑔 1 st v i ω x = 𝑔 i 1 st u x y | y = i ω j ω x = i 𝑔 j
4 1 2 3 mp2b Sat = rec f V f x y | y = u f v f x = 1 st u 𝑔 1 st v i ω x = 𝑔 i 1 st u x y | y = i ω j ω x = i 𝑔 j
5 omex ω V
6 5 5 xpex ω × ω V
7 xpexg ω V ω × ω V ω × ω × ω V
8 simpl ω V ω × ω V ω V
9 goelel3xp i ω j ω i 𝑔 j ω × ω × ω
10 eleq1 x = i 𝑔 j x ω × ω × ω i 𝑔 j ω × ω × ω
11 9 10 syl5ibrcom i ω j ω x = i 𝑔 j x ω × ω × ω
12 11 rexlimivv i ω j ω x = i 𝑔 j x ω × ω × ω
13 12 ad2antll ω V ω × ω V y = i ω j ω x = i 𝑔 j x ω × ω × ω
14 eleq1 y = y ω ω
15 1 14 mpbiri y = y ω
16 15 ad2antrl ω V ω × ω V y = i ω j ω x = i 𝑔 j y ω
17 7 8 13 16 opabex2 ω V ω × ω V x y | y = i ω j ω x = i 𝑔 j V
18 5 6 17 mp2an x y | y = i ω j ω x = i 𝑔 j V
19 18 rdg0 rec f V f x y | y = u f v f x = 1 st u 𝑔 1 st v i ω x = 𝑔 i 1 st u x y | y = i ω j ω x = i 𝑔 j = x y | y = i ω j ω x = i 𝑔 j
20 4 19 eqtri Sat = x y | y = i ω j ω x = i 𝑔 j