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Theorem hbnOLD 1777
Description: Obsolete proof of hbn 1776 as of 16-Dec-2017. (Contributed by NM, 5-Aug-1993.) (Proof modification is discouraged.) (New usage is discouraged.)
Hypothesis
Ref Expression
hbn.1 (φxφ)
Assertion
Ref Expression
hbnOLD φx ¬ φ)

Proof of Theorem hbnOLD
StepHypRef Expression
1 sp 1747 . . 3 (xφφ)
21con3i 127 . 2 φ → ¬ xφ)
3 hbn1 1730 . . 3 xφx ¬ xφ)
4 hbn.1 . . . 4 (φxφ)
54con3i 127 . . 3 xφ → ¬ φ)
63, 5alrimih 1565 . 2 xφx ¬ φ)
72, 6syl 15 1 φx ¬ φ)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wal 1540
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
This theorem is referenced by: (None)
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