Metamath Proof Explorer


Theorem 2uasban

Description: Distribute the unabbreviated form of proper substitution in and out of a conjunction. (Contributed by Alan Sare, 31-May-2014) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion 2uasban
|- ( E. x E. y ( ( x = u /\ y = v ) /\ ( ph /\ ps ) ) <-> ( E. x E. y ( ( x = u /\ y = v ) /\ ph ) /\ E. x E. y ( ( x = u /\ y = v ) /\ ps ) ) )

Proof

Step Hyp Ref Expression
1 biid
 |-  ( ( E. x E. y ( ( x = u /\ y = v ) /\ ph ) /\ E. x E. y ( ( x = u /\ y = v ) /\ ps ) ) <-> ( E. x E. y ( ( x = u /\ y = v ) /\ ph ) /\ E. x E. y ( ( x = u /\ y = v ) /\ ps ) ) )
2 1 2uasbanh
 |-  ( E. x E. y ( ( x = u /\ y = v ) /\ ( ph /\ ps ) ) <-> ( E. x E. y ( ( x = u /\ y = v ) /\ ph ) /\ E. x E. y ( ( x = u /\ y = v ) /\ ps ) ) )