Metamath Proof Explorer


Theorem tz9.1c

Description: Alternate expression for the existence of transitive closures tz9.1 : the intersection of all transitive sets containing A is a set. (Contributed by Mario Carneiro, 22-Mar-2013)

Ref Expression
Hypothesis tz9.1.1 A V
Assertion tz9.1c x | A x Tr x V

Proof

Step Hyp Ref Expression
1 tz9.1.1 A V
2 eqid rec z V z z A ω = rec z V z z A ω
3 eqid w ω rec z V z z A ω w = w ω rec z V z z A ω w
4 1 2 3 trcl A w ω rec z V z z A ω w Tr w ω rec z V z z A ω w x A x Tr x w ω rec z V z z A ω w x
5 3simpa A w ω rec z V z z A ω w Tr w ω rec z V z z A ω w x A x Tr x w ω rec z V z z A ω w x A w ω rec z V z z A ω w Tr w ω rec z V z z A ω w
6 omex ω V
7 fvex rec z V z z A ω w V
8 6 7 iunex w ω rec z V z z A ω w V
9 sseq2 x = w ω rec z V z z A ω w A x A w ω rec z V z z A ω w
10 treq x = w ω rec z V z z A ω w Tr x Tr w ω rec z V z z A ω w
11 9 10 anbi12d x = w ω rec z V z z A ω w A x Tr x A w ω rec z V z z A ω w Tr w ω rec z V z z A ω w
12 8 11 spcev A w ω rec z V z z A ω w Tr w ω rec z V z z A ω w x A x Tr x
13 4 5 12 mp2b x A x Tr x
14 abn0 x | A x Tr x x A x Tr x
15 13 14 mpbir x | A x Tr x
16 intex x | A x Tr x x | A x Tr x V
17 15 16 mpbi x | A x Tr x V