Metamath Proof Explorer


Theorem trintALT

Description: The intersection of a class of transitive sets is transitive. Exercise 5(b) of Enderton p. 73. trintALT is an alternate proof of trint . trintALT is trintALTVD without virtual deductions and was automatically derived from trintALTVD using the tools program translate..without..overwriting.cmd and the Metamath program "MM-PA> MINIMIZE__WITH *" command. (Contributed by Alan Sare, 17-Apr-2012) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion trintALT x A Tr x Tr A

Proof

Step Hyp Ref Expression
1 simpl z y y A z y
2 1 a1i x A Tr x z y y A z y
3 iidn3 x A Tr x z y y A q A q A
4 id x A Tr x x A Tr x
5 rspsbc q A x A Tr x [˙q / x]˙ Tr x
6 3 4 5 ee31 x A Tr x z y y A q A [˙q / x]˙ Tr x
7 trsbc q A [˙q / x]˙ Tr x Tr q
8 7 biimpd q A [˙q / x]˙ Tr x Tr q
9 3 6 8 ee33 x A Tr x z y y A q A Tr q
10 simpr z y y A y A
11 10 a1i x A Tr x z y y A y A
12 elintg y A y A q A y q
13 12 ibi y A q A y q
14 11 13 syl6 x A Tr x z y y A q A y q
15 rsp q A y q q A y q
16 14 15 syl6 x A Tr x z y y A q A y q
17 trel Tr q z y y q z q
18 17 expd Tr q z y y q z q
19 9 2 16 18 ee323 x A Tr x z y y A q A z q
20 19 ralrimdv x A Tr x z y y A q A z q
21 elintg z y z A q A z q
22 21 biimprd z y q A z q z A
23 2 20 22 syl6c x A Tr x z y y A z A
24 23 alrimivv x A Tr x z y z y y A z A
25 dftr2 Tr A z y z y y A z A
26 24 25 sylibr x A Tr x Tr A