Theorem wl-nfsbtv 37558

Description: Closed form of nfsbv 2329. (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 2066	. 2 ⊢ (∀𝑥Ⅎ𝑧𝜑 → [𝑦 / 𝑥]Ⅎ𝑧𝜑)
2		sbnf 2311	. 2 ⊢ ([𝑦 / 𝑥]Ⅎ𝑧𝜑 ↔ Ⅎ𝑧[𝑦 / 𝑥]𝜑)
3	1, 2	sylib 218	1 ⊢ (∀𝑥Ⅎ𝑧𝜑 → Ⅎ𝑧[𝑦 / 𝑥]𝜑)

Syntax hints:   → wi 4  ∀wal 1535  Ⅎwnf 1780  [wsb 2062

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-10 2139  ax-11 2155  ax-12 2175

This theorem depends on definitions:  df-bi 207  df-an 396  df-ex 1777  df-nf 1781  df-sb 2063

This theorem is referenced by:  wl-sb8eutv  37560