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Theorem 19.19 1862
Description: Theorem 19.19 of [Margaris] p. 90. (Contributed by NM, 5-Aug-1993.)
Hypothesis
Ref Expression
19.19.1 xφ
Assertion
Ref Expression
19.19 (x(φψ) → (φxψ))

Proof of Theorem 19.19
StepHypRef Expression
1 19.19.1 . . 3 xφ
2119.9 1783 . 2 (xφφ)
3 exbi 1581 . 2 (x(φψ) → (xφxψ))
42, 3syl5bbr 250 1 (x(φψ) → (φxψ))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 176  wal 1540  wex 1541  wnf 1544
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 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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