Theorem wl-nfsbtv 38701

Description: Closed form of nfsbv 2364. (Contributed by Wolf Lammen, 2-May-2025.)

Assertion

Ref	Expression
wl-nfsbtv	⊢ (∀𝑥Ⅎ𝑧𝜑 → Ⅎ𝑧[𝑦 / 𝑥]𝜑)

Distinct variable groups:   𝑥,𝑧   𝑦,𝑧

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

Proof of Theorem wl-nfsbtv

Step	Hyp	Ref	Expression
1		stdpc4 2107	. 2 ⊢ (∀𝑥Ⅎ𝑧𝜑 → [𝑦 / 𝑥]Ⅎ𝑧𝜑)
2		sbnf 2348	. 2 ⊢ ([𝑦 / 𝑥]Ⅎ𝑧𝜑 ↔ Ⅎ𝑧[𝑦 / 𝑥]𝜑)
3	1, 2	sylib 221	1 ⊢ (∀𝑥Ⅎ𝑧𝜑 → Ⅎ𝑧[𝑦 / 𝑥]𝜑)

This proof depends on syntax axioms:   → wi 4  ∀wal 1568  Ⅎwnf 1816  [wsb 2101

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-10 2180  ax-11 2197  ax-12 2216

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-nf 1817  df-sb 2102

This theorem is used by:  wl-sb8eutv  38703