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Theorem 19.9OLD 1784
Description: Obsolete proof of 19.9 1783 as of 30-Dec-2017. (Contributed by FL, 24-Mar-2007.) (Revised by Mario Carneiro, 24-Sep-2016.) (Proof modification is discouraged.) (New usage is discouraged.)
Hypothesis
Ref Expression
19.9.1 xφ
Assertion
Ref Expression
19.9OLD (xφφ)

Proof of Theorem 19.9OLD
StepHypRef Expression
1 19.9.1 . 2 xφ
2 19.9t 1779 . 2 (Ⅎxφ → (xφφ))
31, 2ax-mp 5 1 (xφφ)
Colors of variables: wff setvar class
Syntax hints:  wb 176  wex 1541  wnf 1544
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-11 1746
This theorem depends on definitions:  df-bi 177  df-ex 1542  df-nf 1545
This theorem is referenced by: (None)
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