Theorem alseubii 17185

Description: Congruence: equivalents may be substituted inside an "all some one". This is the "all some one" counterpart of alsbii 17153. (Contributed by David A. Wheeler, 22-Jul-2026.)

Hypotheses

Ref	Expression
alseubii.1	|- ( ph <-> ch )
alseubii.2	|- ( ps <-> th )

Assertion

Ref	Expression
alseubii	|- ( A.E! x ( ph -> ps ) <-> A.E! x ( ch -> th ) )

Proof of Theorem alseubii

Step	Hyp	Ref	Expression
1		alseubii.1	. . . . 5 |- ( ph <-> ch )
2		alseubii.2	. . . . 5 |- ( ps <-> th )
3	1, 2	imbi12i 239	. . . 4 |- ( ( ph -> ps ) <-> ( ch -> th ) )
4	3	albii 1523	. . 3 |- ( A. x ( ph -> ps ) <-> A. x ( ch -> th ) )
5	1	eubii 2095	. . 3 |- ( E! x ph <-> E! x ch )
6	4, 5	anbi12i 464	. 2 |- ( ( A. x ( ph -> ps ) /\ E! x ph ) <-> ( A. x ( ch -> th ) /\ E! x ch ) )
7		df-alseu 17174	. 2 |- ( A.E! x ( ph -> ps ) <-> ( A. x ( ph -> ps ) /\ E! x ph ) )
8		df-alseu 17174	. 2 |- ( A.E! x ( ch -> th ) <-> ( A. x ( ch -> th ) /\ E! x ch ) )
9	6, 7, 8	3bitr4i 212	1 |- ( A.E! x ( ph -> ps ) <-> A.E! x ( ch -> th ) )

This proof depends on syntax axioms:   -> wi 4   /\ wa 104   <-> wb 105   A.wal 1400   E!weu 2086   A.E!walseu 17172

This proof depends on 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-ial 1587

This proof depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-eu 2089  df-alseu 17174

This theorem is used by: (None)