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Theorem hblem 2458
Description: Change the free variable of a hypothesis builder. Lemma for nfcrii 2483. (Contributed by NM, 5-Aug-1993.) (Revised by Andrew Salmon, 11-Jul-2011.)
Hypothesis
Ref Expression
hblem.1 ⊢ (y ∈ A → ∀x y ∈ A)
Assertion
Ref Expression
hblem ⊢ (z ∈ A → ∀x z ∈ A)
Distinct variable groups:   y,A   x,z
Allowed substitution hints:   A(x, z)

Proof of Theorem hblem
StepHypRef Expression
1 hblem.1 . . 3 ⊢ (y ∈ A → ∀x y ∈ A)
21hbsb 2110 . 2 ⊢ ([z / y]y ∈ A → ∀x[z / y]y ∈ A)
3 clelsb1 2455 . 2 ⊢ ([z / y]y ∈ A ↔ z ∈ A)
43albii 1566 . 2 ⊢ (∀x[z / y]y ∈ A ↔ ∀x z ∈ A)
52, 3, 43imtr3i 256 1 ⊢ (z ∈ A → ∀x z ∈ A)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4  ∀wal 1540  [wsb 1648   ∈ wcel 1710
This proof depends on 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  ax-12 1925  ax-ext 2334
This proof depends on definitions:  df-bi 177  df-or 359  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-cleq 2346  df-clel 2349
This theorem is used by:  nfcrii  2483
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