Theorem nfsbd 2526

Description: Deduction version of nfsb 2527. (Contributed by NM, 15-Feb-2013.) Usage of this theorem is discouraged because it depends on ax-13 2372. Use nfsbv 2328 instead. (New usage is discouraged.)

Hypotheses

Ref	Expression
nfsbd.1	⊢ Ⅎ𝑥𝜑
nfsbd.2	⊢ (𝜑 → Ⅎ𝑧𝜓)

Assertion

Ref	Expression
nfsbd	⊢ (𝜑 → Ⅎ𝑧[𝑦 / 𝑥]𝜓)

Distinct variable group:   𝑦,𝑧

Allowed substitution hints:   𝜑(𝑥,𝑦,𝑧)   𝜓(𝑥,𝑦,𝑧)

Proof of Theorem nfsbd

Step	Hyp	Ref	Expression
1		nfsbd.1	. . . 4 ⊢ Ⅎ𝑥𝜑
2		nfsbd.2	. . . 4 ⊢ (𝜑 → Ⅎ𝑧𝜓)
3	1, 2	alrimi 2209	. . 3 ⊢ (𝜑 → ∀𝑥Ⅎ𝑧𝜓)
4		nfsb4t 2503	. . 3 ⊢ (∀𝑥Ⅎ𝑧𝜓 → (¬ ∀𝑧 𝑧 = 𝑦 → Ⅎ𝑧[𝑦 / 𝑥]𝜓))
5	3, 4	syl 17	. 2 ⊢ (𝜑 → (¬ ∀𝑧 𝑧 = 𝑦 → Ⅎ𝑧[𝑦 / 𝑥]𝜓))
6		axc16nf 2258	. 2 ⊢ (∀𝑧 𝑧 = 𝑦 → Ⅎ𝑧[𝑦 / 𝑥]𝜓)
7	5, 6	pm2.61d2 181	1 ⊢ (𝜑 → Ⅎ𝑧[𝑦 / 𝑥]𝜓)

Syntax hints:  ¬ wn 3   → wi 4  ∀wal 1537  Ⅎwnf 1787  [wsb 2068

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-10 2139  ax-11 2156  ax-12 2173  ax-13 2372

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-tru 1542  df-ex 1784  df-nf 1788  df-sb 2069

This theorem is referenced by:  nfsb  2527  nfabd  2931  wl-sb8eut  35659