Theorem sbv 1949

Description: Substitution for a variable not occurring in a proposition. See sbf 1830 for a version without disjoint variable condition on x , ph. If one adds a disjoint variable condition on x , t, then sbv 1949 can be proved directly by chaining equsv 1938 with sb6 1941. (Contributed by BJ, 22-Dec-2020.)

Assertion

Ref	Expression
sbv	|- ( [ t / x ] ph <-> ph )

Distinct variable group:   ph, x

Allowed substitution hint:   ph( t)

Proof of Theorem sbv

Step	Hyp	Ref	Expression
1		ax-17 1579	. 2 |- ( ph -> A. x ph )
2	1	sbh 1829	1 |- ( [ t / x ] ph <-> ph )

Syntax hints:   <-> wb 105   [wsb 1815

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587

This theorem depends on definitions:  df-bi 117  df-sb 1816

This theorem is referenced by:  ab0w  3550