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Theorem hb3an 2305
Description: If 𝑥 is not free in 𝜑, 𝜓, and 𝜒, it is not free in (𝜑𝜓𝜒). (Contributed by NM, 14-Sep-2003.) (Proof shortened by Wolf Lammen, 2-Jan-2018.)
Hypotheses
Ref Expression
hb.1 (𝜑 → ∀𝑥𝜑)
hb.2 (𝜓 → ∀𝑥𝜓)
hb.3 (𝜒 → ∀𝑥𝜒)
Assertion
Ref Expression
hb3an ((𝜑𝜓𝜒) → ∀𝑥(𝜑𝜓𝜒))

Proof of Theorem hb3an
StepHypRef Expression
1 hb.1 . . . 4 (𝜑 → ∀𝑥𝜑)
21nf5i 2146 . . 3 𝑥𝜑
3 hb.2 . . . 4 (𝜓 → ∀𝑥𝜓)
43nf5i 2146 . . 3 𝑥𝜓
5 hb.3 . . . 4 (𝜒 → ∀𝑥𝜒)
65nf5i 2146 . . 3 𝑥𝜒
72, 4, 6nf3an 1900 . 2 𝑥(𝜑𝜓𝜒)
87nf5ri 2196 1 ((𝜑𝜓𝜒) → ∀𝑥(𝜑𝜓𝜒))
Colors of variables: wff setvar class
Syntax hints:  wi 4  w3a 1087  wal 1535
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-10 2141  ax-12 2178
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-3an 1089  df-tru 1540  df-ex 1778  df-nf 1782
This theorem is referenced by:  bnj982  34754  bnj1276  34790  bnj1350  34801
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