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Theorem 19.12OLD 1848
Description: Obsolete proof of 19.12 1847 as of 3-Jan-2018. (Contributed by NM, 5-Aug-1993.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
19.12OLD (xyφyxφ)

Proof of Theorem 19.12OLD
StepHypRef Expression
1 hba1 1786 . . 3 (yφyyφ)
21hbex 1841 . 2 (xyφyxyφ)
3 sp 1747 . . 3 (yφφ)
43eximi 1576 . 2 (xyφxφ)
52, 4alrimih 1565 1 (xyφyxφ)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wal 1540  wex 1541
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746
This theorem depends on definitions:  df-bi 177  df-ex 1542
This theorem is referenced by: (None)
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